Sunday

March 29, 2015

March 29, 2015

**Recent Homework Questions About Statistics**

Post a New Question | Current Questions

**Statistics**

A sample of n = 9 scores is obtained from a population with ƒÝ = 70 and ƒã = 18. If the sample mean is M = 76, then what is the z-score for the sample mean? a. z = 0.33 b. z = 0.50 c. z = 1.00 d. z = 3.00
*Monday, December 9, 2013 at 7:32pm*

**STATISTICS HELP**

A student wishes to test the accuracy of the measuring jug she is using in an experiment. The label on the jug claims that it measures volume to an accuracy of plus or minus 5 cm3. The density of water is about 0.999 g cm−3, which means that 100 cm3 of water should have ...
*Monday, December 9, 2013 at 8:17am*

**Statistics**

Suppose that you visit Shire, and find that 28% of Hobbits believe in the existence of Elves, 16% believe in the existence of Ents, and 9% believe in the existence of both Elves and Ents. You come across a Hobbit: i) What is the probability that he will believe in Ents given ...
*Sunday, December 8, 2013 at 10:54pm*

**Psychological Statistics**

Post a behavioral research situation that could use a Pearson coefficient research study and a chi square research study. Present the rationale for each selection. Be very specific in your presentation.
*Sunday, December 8, 2013 at 4:33pm*

**Statistics**

The probability of Joe is at work is 49%. The probability Joe is at home is 25%. What is the probability Jow is neither at Work nor at home? A) 39% B)74% C)52% D)26% I get the answer at about 38%,but doesn't round to 39%, can anyone help, I'm stuck.
*Sunday, December 8, 2013 at 4:02pm*

**Statistics**

How would you find the z-score for the following X=86 and the n=17.
*Sunday, December 8, 2013 at 1:28pm*

**Business Math and Statistics**

You deposit $1,000 for 4 years at an interest rate of 2.0%. If the interest is compounded annually, how much money do you have after 4 years?
*Sunday, December 8, 2013 at 1:33am*

**Statistics**

Find the Standard Deviation for this distribution of scores. Then find the z score for X=86. N=17 98, 92, 86, 84 , 76, 74 , 72 , 72, 72 , 70, 70, 66, 60 ,54, 32,30
*Saturday, December 7, 2013 at 9:02pm*

**STATISTICS**

Two-thirds of papaya plants availabe are hermaphrodite and are self-pollinating. One-third of plants are female and need to be paired withh an hermaphrodite plant in order to be pollinated. Unless the plants are pollinated, they will not bear fruit. If you select three papaya ...
*Saturday, December 7, 2013 at 6:06pm*

**Healthcare Statistic**

Given the following null hypothesis, give an example of a Type II error. H0: There is no difference in the level of understanding of this chapter between students who have previously taken a statistics course and students who have not previously taken a statistics course.
*Saturday, December 7, 2013 at 5:50pm*

**Statistics**

Two-thirds of papaya plants availabe are hermaphrodite and are self-pollinating. One-third of plants are female and need to be paired withh an hermaphrodite plant in order to be pollinated. Unless the plants are pollinated, they will not bear fruit. If you select three papaya ...
*Saturday, December 7, 2013 at 4:21pm*

**Easy Statistics**

The probability Joe is at work is 49%,. The probability Joe is at home is 25%. What is the probability Joe is neither at work nor at home? a) 39% b)74% c)52% d) 26% *I personally think it is a or c. I am just needing some help thanks!
*Friday, December 6, 2013 at 9:22pm*

**statistics**

Nine students took the SAT. Their scores are listed below. Later on, they read a book on test preparation and retook the SAT. Their new scores are listed below. Construct a 95% confidence interval for µ d (the true mean difference in scores). Assume that the distribution...
*Friday, December 6, 2013 at 3:39pm*

**statistics**

The espresso project you are heading up will do well with probability 0.80. Given that it does well, you believe that the herbal tea project is likely to do well with probability 0.70.However, if the espresso project does not do well, then the herbal tea project has only a 25...
*Friday, December 6, 2013 at 9:13am*

**Statistics**

Draw a vertical line through a normal distribution for each of the following z-score locations. Determine whether the body is on the right or left side od the line and find the proportion in the body. a. z= 2.20 b. z= 1.60 c. z= -1.50 d. z= -0.70
*Friday, December 6, 2013 at 12:47am*

**Statistics**

Draw a vertical line through s normal distribution for each of the following z-score locations. Determine whether the tail is on the right or left side of the line and find the proportion in the tail. a. z=2.00 b. z=0.60 c. z= -1.30 d. z= -0.30
*Friday, December 6, 2013 at 12:43am*

**Statistics**

A normal distribution has a mean of ƒÝ = 100 with ƒã = 20. If one score is randomly selected from this distribution, what is the probability that the score will have a value between X = 90 and X = 110? a. 0.6915 b. 0.3085 c. 0.1915 d. 0.3830
*Thursday, December 5, 2013 at 8:16pm*

**Statistics**

Given the following information, determine the 68.3 percent, 95.5 percent, and 99.7 percent confidence intervals. overbar above X equals 4.33 comma SE sub m equals 3 I've looked at the table as recommended. I just do not understand this at all. I'm really lost on this ...
*Thursday, December 5, 2013 at 11:54am*

**Statistics**

True or False For any normal distribution, the proportion in the tail beyond z = 2.00 is p = 0.0228.
*Thursday, December 5, 2013 at 7:01am*

**Statistics**

True or False A jar contains 15 red marbles and 75 blue marbles. If you randomly select a marble from this jar, the probability of obtaining a red marble is p = 15/90.
*Thursday, December 5, 2013 at 7:00am*

**Statistics**

True or False One requirement of a random sample is that every individual in the population has an equal chance of being selected.
*Thursday, December 5, 2013 at 6:59am*

**Statistics**

True or False The value for a probability can never be less than zero, unless you have made a computational error.
*Thursday, December 5, 2013 at 6:56am*

**Statistics**

True or False All probabilities can be expressed as decimal values ranging from 0 to 1.00.
*Thursday, December 5, 2013 at 6:54am*

**AP Statistics**

A standard deck of cards consisting of 52 cards, 13 in each of 4 different suits, is shuffled, and 4 cards are drawn without replacement. What is the probability that all four cards are of a different suit?
*Wednesday, December 4, 2013 at 8:24pm*

**statistics**

I have just a couple questions I have trouble understanding... can someone please help me? The data below indicate the rankings of a set of employees according to class theory and on-the-job practice evaluations: Theory 1 7 2 10 4 8 5 3 6 9 Practice 2 8 1 7 3 9 6 5 4 10 What ...
*Wednesday, December 4, 2013 at 2:22pm*

**Statistics**

Your program plans to acquire a total of 600 end items costing $535 million over a five-year period. The first production contract is to be awarded in FY04. The number of items to be procured (not delivered) each year and their estimated cost (in then-year dollars) is shown ...
*Tuesday, December 3, 2013 at 10:03pm*

**statistics**

The average for the statistics exam was 72 and the standard deviation was 4. Kelsey was told by the instructor that she scored 1.85 standard deviations below the mean.
*Tuesday, December 3, 2013 at 4:23am*

**statistics**

The HIM department at community hospital will experience a 15 percent increase in the number of discharges coded per day as a result of opening a cardic clinic in the facility. The 15 percent increase is projected to be 100 additional records per day. The standard time to code...
*Tuesday, December 3, 2013 at 4:05am*

**Statistics**

community physicians clinic is a large clinic with 85 physicians. they treat about 8,600 patients each week. coders are expected to code 100 clinic records each day. how many Full Time Employees are needed to code these records? ( assume a five day work week)
*Monday, December 2, 2013 at 7:41am*

**STATISTICS **

To calculate the mean for grouped data, which of the following steps must be completed? a. multiply the number of subjects within each category by the value of that category b. divide the results of the multiplication c. multiply by the number of subjects d. multiply each ...
*Monday, December 2, 2013 at 5:32am*

**Statistics**

smith is a weld inspector at a shipyard. he knows from keeping track of good and substandard welds that for the afternoon shift 5% of all welds done will be substandard. If Smith checks 300 of the 7500 welds completed that shift, would it be unusual for Smith to find 30 or ...
*Sunday, December 1, 2013 at 10:21pm*

**Statistics**

1. The Chi-square distribution, used in the Chi-square test of independence, varies in shape by degrees of freedom. What does the Chi-square distribution look like for 4 degrees of freedom. A) Unimodal and symmetric. B) Bimodal and symmetric. C) Unimodal and skewed to the left...
*Sunday, December 1, 2013 at 8:14pm*

**Statistics **

Explaining confidence. A student reads that a 95% confidence interval for the mean ideal weight given by adult American women is 140 ± 1.4 pounds. Asked to explain the meaning of this interval, the student says, “95% of all adult American women would say that ...
*Sunday, December 1, 2013 at 8:09pm*

**Statistics**

Suppose 5 cards are drawn, without replacement, from a standard bridge deck of 52 cards. Find the probability of drawing 4 clubs and 1 non- club.
*Sunday, December 1, 2013 at 4:26pm*

**Statistics 2**

To calculate the mean for grouped data, which of the following steps must be completed? a. multiply the number of subjects within each category by the value of that category b. divide the results of the multiplication c. multiply by the number of subjects d. multiply each ...
*Sunday, December 1, 2013 at 2:05pm*

**Statistics 1**

Professor White asked his students to put the number of hours each studied for the final exam on a piece of paper and turn that paper in with the exam. The pieces of paper indicate that students studied 10, 3, 4, 25, 1, 4, 4, 12, 6, 8, and 10 hours. What is the mean number of ...
*Sunday, December 1, 2013 at 2:03pm*

**elementary statistics**

A statistics professor is used to having a variance in his class grades of no more than 100. He feels that his current group of students is different, and so he examines a random sample of midterm grades (listed below). At 0.05 alpha level can it be conculded that the variance...
*Saturday, November 30, 2013 at 10:30pm*

**Statistics**

Of the parts produced by a particular machine, 1.5% are defective. If a random sample of 11 parts produced by this machine contains 2 or more defective parts, the machine is shut down for repairs. Find the probability that the machine will be shut down for repairs based on ...
*Saturday, November 30, 2013 at 9:55pm*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...
*Saturday, November 30, 2013 at 8:06pm*

**elementary statistics**

A statistics professor is used to having a variance in his class grades of no more than 100. He feels that his current group of students is different, and so he examines a random sample of midterm grades (listed below). At 0.05 alpha level can it be conculded that the variance...
*Saturday, November 30, 2013 at 7:44pm*

**statistics**

Ala rge fleet of cars is maintained with an average of 26 mpg. 50 recent trips displayed a mean of 25.02 mpg and standard deviation of 4.1 mpg. At the 5% level of significance, is their evidence the company has failed to keep their fuel goals? I did the math and got .03380315...
*Saturday, November 30, 2013 at 12:27pm*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...
*Saturday, November 30, 2013 at 1:50am*

**Statistics**

I have two coins: a quarter and a nickel. The quarter has a bias of 1/4 for heads, and the nickel has a bias of 2/3 for heads. I flip each coin 10 times. What is the probability that I observe exactly five heads total? Some explanation of the solution would be appreciated.
*Friday, November 29, 2013 at 11:04pm*

**Statistics**

Hello, my problem is I have a random sample of only 15 sales average is $115 with a known population standard deviation of $25.00. Obtain a 92% confidence interval and explain what your answer means. I am not sure what to do because the sample size is only 15. Thanks for your ...
*Friday, November 29, 2013 at 8:00pm*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...
*Friday, November 29, 2013 at 7:30pm*

**statistics**

In a distribution of sentence lengths in months like the following: 6, 12, 10, 18, 24, 360; which statistic would a researcher not want to report? a. standard deviation b. mean c. range d. raw numbers
*Friday, November 29, 2013 at 8:13am*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...
*Thursday, November 28, 2013 at 5:13pm*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...
*Wednesday, November 27, 2013 at 11:34pm*

**Statistics**

A statistics professor plans her classes so carefully that the lengths of her class are uniformly distributed between 46.0 and 56.0 minutes. Find the probablity that given class period runs less than 51.75 minutes
*Wednesday, November 27, 2013 at 3:47am*

**Statistics**

A clinical trial tests a method designed to increase the probability of conceiving a girl. In the study, 449 babies were born, and 250 of them were girls. Use the sample data with .01 significance level to test the claim that with this method, the probability of a baby being a...
*Tuesday, November 26, 2013 at 6:03pm*

**statistics**

A particular country has 55 total states. If the areas of 30 states are added and the sum is divided by 30, the result is 196,582 square kilometers. Determine whether this result is a statistic or a parameter and why.
*Tuesday, November 26, 2013 at 1:02pm*

**statistics**

With n=13 and p= 0.7, find the binomial probability p(9) by using a binomial probability table. If np> and nq> 5, also estimate the indicated probability by using the normal distribution as an approximation to the binomial, if np<5 or nq<5 then state that the ...
*Monday, November 25, 2013 at 9:36pm*

**Statistics**

An industrial psychologist has a stress test that is used to determine the amount of stress that managers are under. A value of 80 or higher indicates “high stress.” The industrial psychologist believes that the managers at a large, profitable pharmaceutical firm are...
*Monday, November 25, 2013 at 5:22pm*

**statistics**

In a study of caffeine and stress, college students indicate how many cups of coffee they drink per day and their stress level on a scale of 1-10. The data appear below. Number of Cups of Coffee Stress Level 3 5 2 3 4 3 6 9 5 4 1 2 7 10 3 5 = 3.88 X= 5.13 s = 2.03 s = 2.90 ...
*Monday, November 25, 2013 at 3:36pm*

**statistics psy/315**

Based on the information given for each of the following studies, decide whether to reject the null hypothesis.For each, give (a) the Z-score cutoff (or cutoffs) on the comparison distribution at which the null hypothesis should be rejected(b) the Z score on the comparison ...
*Monday, November 25, 2013 at 11:12am*

**statistics**

A clinical trial tests a method designed to increase the probability of conceiving a girl. In a study 306 babies were born, and 174 of them were girls. the sample data with a 0.01 significance level to test the claim that with this method, the probability of being a girl is ...
*Monday, November 25, 2013 at 10:25am*

**Statistics**

n two separate studies, the actual difference between the means of a treated group and an untreated group is 3 points. However, in one study, the ÏƒM1-M2 is very large and so the 3 points is not found to be significant. In the other study, the ÏƒM1-M2 is ...
*Monday, November 25, 2013 at 7:18am*

**statistics**

how would you tell deviations from normality by looking at a box plot?
*Sunday, November 24, 2013 at 7:11pm*

**statistics**

how would you tell deviations from normality by looking at a box plot?
*Sunday, November 24, 2013 at 7:08pm*

**statistics**

what makes a probability plot non-normal? I would think outliers are one of them, but what else?
*Sunday, November 24, 2013 at 7:06pm*

**Statistics**

Given the following information, determine the 68.3 percent, 95.5 percent, and 99.7 percent confidence intervals. overbar above X equals 4.33 comma SE sub m equals 3 I would appreciate it extremely if someone would help me figure this out. I honestly have no idea how to do ...
*Sunday, November 24, 2013 at 6:33pm*

**statistics**

Typing speeds among college students are normally distributed with a mean of 60 words, and a standard deviation of 10 words. determine the typing speed that separates the top 6% typists from the rest.
*Sunday, November 24, 2013 at 3:55pm*

**statistics**

1. A professor measured the time (in seconds) required to catch a falling meter stick for 19 randomly selected students’ dominant and non-dominant hand. The professor claims that the reaction time in an individual’s dominant hand is less than the reaction time in ...
*Sunday, November 24, 2013 at 3:33pm*

**Statistics**

142 out of 507 people were right. Calculate a 95% confidence interval for the proportion of the entire population that could be right. I did some of the work …Please help. I am getting .0199 SD =sqt(.28(1-.28)/506 = .0119 so .28 +/- .0119 so I could say that with 95% ...
*Sunday, November 24, 2013 at 3:08pm*

**Statistics**

142 out of 507 people were right. Calculate a 95% confidence interval for the proportion of the entire population that could be right. I did some of the work and got .72...don't know what to do with this? Please help.
*Sunday, November 24, 2013 at 1:45pm*

**Statistics**

A sample of 11 observations taken from a normally distributed population produced the following data. −7.1 10.3 8.7 −3.6 −6.0 −7.5 5.2 3.7 9.8 −4.4 6.4 a) What is the point estimate of μ? b) Make a 95% confidence interval for μ. c) What ...
*Sunday, November 24, 2013 at 12:25pm*

**Statistics**

Many dairy cows now receive injections of BST, a hormone intended to spur greater milk production. A group of 53 Jersey cows increased average milk production from 43 to 52 pounds per day, with a standard deviation of 4.8 lbs. Is this evidence that the hormone maybe effective ...
*Sunday, November 24, 2013 at 9:14am*

**statistics**

For the past 20 years, the high temperature on April 15th has averaged = 62 degrees with a standard deviation of = 12. Last year, the high temperature was 68 degrees. Based on this information, which of the following best describes last year's temperature...
*Sunday, November 24, 2013 at 2:42am*

**Statistics**

Exercise 8.92 Tony's Pizza guarantees all pizza deliveries within 30 minutes of the placement of orders. An agency wants to estimate the proportion of all pizzas delivered within 30 minutes by Tony's. What is the most conservative estimate of the sample size that would...
*Saturday, November 23, 2013 at 6:10pm*

**Statistics**

Tony's Pizza guarantees all pizza deliveries within 30 minutes of the placement of orders. An agency wants to estimate the proportion of all pizzas delivered within 30 minutes by Tony's. What is the most conservative estimate of the sample size that would limit the ...
*Saturday, November 23, 2013 at 6:08pm*

**statistics**

If the average commute time is 10.9 miles, but the average is actually the mean of a sample of 300 commuters and the sample standard deviation is 6.2 miles Estimate the true mean commute distance using 99% confidence level.
*Saturday, November 23, 2013 at 3:00pm*

**Statistics**

125/500 women soda drinkers indicate they drink diet soda. At the .01 level, does this evidence indicate that more than 20% of the women soda drinkers drink diet soda? Determine and explain the P-value please. I have the numbers...just cannot explain. Please help.
*Saturday, November 23, 2013 at 2:51pm*

**statistics**

Failing to reject the null hypothesis when it is false is a Type II Error. T or F, and why or why not?
*Saturday, November 23, 2013 at 10:30am*

**statistics**

IQ scores were obtained from randomly selected couples.For 20 such pairs of people, the linear correlation coefficient is 0.881 and the equation of the regression line is y= -6.93+ 10.8x, where x represents the IQ score of the husband. Also, the 20x values have a mean of 105....
*Saturday, November 23, 2013 at 8:42am*

**statistics**

Assume that thermometer readings are normally distributed with a mean of 0.0 and a standard deviation of 1,00. the thermometer is randomly selected and tested. For the case below, draw a sketch , and find the probability of the reading The given values in Celsius degrees) ...
*Friday, November 22, 2013 at 2:09pm*

**statistics**

Is there a significant difference between first year post college incomes of graduates from public versus private institutions? Provide the IV, DV, and best method of analysi
*Thursday, November 21, 2013 at 9:41pm*

**Statistics**

Many dairy cows now receive injections of BST, a hormone intended to spur greater milk production. A group of 53 Jersey cows increased average milk production from 43 to 52 pounds per day, with a standard deviation of 4.8 lbs. Is this evidence that the hormone maybe effective ...
*Thursday, November 21, 2013 at 7:31pm*

**Statistics**

If the cases selected for one sample have no influence upon the cases selected for a second sample, then the samples are said to be: A) independent B) inconsistent C) dependent D) consistent A
*Thursday, November 21, 2013 at 7:27pm*

**Statistics**

The effectiveness of a headache medicine is tested by measuring the intensity of a headache in patients before and after drug treatment. The data consist of before and after intensities for each patient. Identify the design of the study. A) Paired t-test B) Two-sample t-test C...
*Thursday, November 21, 2013 at 6:40pm*

**Statistics**

A researcher wished to test the effect of the addition of extra calcium to yogurt on the "tastiness" of yogurt. Two different yogurts, one with extra calcium and one without the added calcium, were created from the same batch of yogurt. A group of 84 adult volunteers...
*Thursday, November 21, 2013 at 6:39pm*

**statistics 201**

A firm hires a pool of financial consultants to discuss portfolio recommendations with its clients. The CEO believes that another financial consultant should be hired if the average phone consultation exceeds 350 seconds. A random sample of 100 phone calls revealed a mean of ...
*Thursday, November 21, 2013 at 2:48pm*

**Statistics**

The standard deviation for a population is σ = 15.3. A sample of 36 observations selected from this population gave a mean equal to 74.8. a) Make a 90% confidence interval for μ b) Construct a 95% confidence interval for μ. c) Determine a 99% confidence interval...
*Thursday, November 21, 2013 at 11:11am*

**Statistics**

Given the following null hypothesis, give an example of a Type II error. Ho: There is no difference in the level of understanding of this chapter between students who have previously taken a statistics course and students who have not previously takn a stastics course.
*Thursday, November 21, 2013 at 9:55am*

**Statistics**

given the following null hypothesis, give an example of a type I error. Ho: There is no difference between the number of males or females who go to their primary care physician for an annual exam.
*Thursday, November 21, 2013 at 9:53am*

**Statistics**

given the following information, determine the 68.3 percent, 95.5 percent, and 99.7 percent confidence intervals. Mean = 4.33, standard error of the mean =3
*Thursday, November 21, 2013 at 9:46am*

**Statistics**

Create a null hypothesis for the following research questions: a. What are the differences between emergency room shifts on medication errors? b. On a clinical trial of a new drug, what will be the effects over a currently used drug?
*Thursday, November 21, 2013 at 9:41am*

**statistics**

conduct a study on support of ban on smartphones in class. 68/87 said yes. How large of a sample is needed to be sure the margin of error +/- 3.5% with 99% confidence. I know this is estimation...but I am not sure how to go about solving this problem.
*Wednesday, November 20, 2013 at 9:38pm*

**statistics**

I am conducting a study on support of ban on smartphones in class. 68/87 said yes to the ban. How large of a sample is needed to be sure the margin of error +/- 3.5% with 99% confidence. I know this is estimation...but I am not sure how to go about solving this problem.
*Wednesday, November 20, 2013 at 9:19pm*

**Statistics**

Most people are definitely dominant on one side of their body - either right or left. For some sports being able to use both sides is an advantage, such as batting in baseball or softball. In order to determine if there is a difference in strength between the dominant and non-...
*Wednesday, November 20, 2013 at 8:03pm*

**Statistics**

A packing company investigates a national training consultant in hopes of improving productivity on the packing line. The national consultant agrees to work with 18 employees, collecting productivity data for each employee before the training program and after the training ...
*Wednesday, November 20, 2013 at 8:02pm*

**Statistics**

When comparing two samples that are independent of one another, we use the two-sample t-test. A) True B) False 5. Using paired differences helps to reduce the variation. A) True B) False Both are True?
*Wednesday, November 20, 2013 at 4:48pm*

**Statistics**

Create a null hypothesis for the following research questions: a. What are the differences between emergency room shifts on medication errors? b. On a clinical trial of a new drug, what will be the effects over a currently used drug?
*Wednesday, November 20, 2013 at 9:29am*

**Statistics**

How could you reword these research hypotheses to null hypotheses? a. Smoking during pregnancy increase the risk of a child being born prematurely. b. Regular exercises in older adults decreases blood pressure levels.
*Wednesday, November 20, 2013 at 9:29am*

**Statistics**

Given the following p values which would be considered more significant? a) p ≤ 0.3 b) p ≤ 0.02 c) p ≤ 0.25
*Wednesday, November 20, 2013 at 9:28am*

**Statistics**

Battery manufacturers compete on the basis of the amount of time their products last in cameras and toys. A manufacturer of alkaline batteries has observed that it's batteries last for an average of 26 hours when used in a toy racing car. The amount of time is normally ...
*Wednesday, November 20, 2013 at 4:23am*

**statistics**

You randomly choose 16 unfurnished one-bedroom apartments from a large number of advertisements in your local newspaper. You calculate that their mean monthly rent is $613 and their standard deviation is $96. Does this SRS give good reason to believe that the mean rent of all ...
*Tuesday, November 19, 2013 at 8:58pm*

**statistics**

A group of 49 randomly selected construction workers has a mean age of 22.4 years with a standard deviation of 3.8. According to a recent survey, the mean age should be mu=21.9. Test this hypothesis by constructing a 98% confidence interval for the population mean.
*Tuesday, November 19, 2013 at 6:31pm*

**statistics**

In a study designed to test the effectiveness of magnets for treating back pain, 40 patients were given a treatment with magnets and also a sham treatment without magnets. Pain was measured using a scale from 0 to 100. After given the magnet treatments, the 40 patients had ...
*Tuesday, November 19, 2013 at 6:20pm*

**statistics**

A data set includes 108 body temperatures of healthy adult humans for which x is 98.2 degrees and s is 0.64 degrees. What is the best point estimate of the mean body temperature of all healthy humans?
*Tuesday, November 19, 2013 at 5:57pm*

**statistics**

A study of the time spent shopping in a supermarket for a market basket of 20 specific items showed an approximately uniform distribution between 20 minutes and 40 minutes. What is the probability that the shopping rime will be a. Between 25 and 30 minutes? b. less than 35 ...
*Tuesday, November 19, 2013 at 10:54am*

Pages: <<Prev | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | **17** | 18 | 19 | 20 | 21 | 22 | 23 | Next>>

Post a New Question | Current Questions