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April 20, 2014

April 20, 2014

**Recent Homework Questions About Statistics**

Post a New Question | Current Questions

**Statistics**

true
*Thursday, December 5, 2013 at 9:54am*

**Statistics**

true, but your answer should be reduced to 1/6
*Thursday, December 5, 2013 at 9:52am*

**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**

joij
*Wednesday, December 4, 2013 at 5:33pm*

**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**

You might want to round it to the nearest person. It rounds to 17, but if you want all the records to be covered, you might round it up to 18. This would give the FTEs a little slack.
*Tuesday, December 3, 2013 at 1:00pm*

**statistics**

(100*10)/(7*60) = ?
*Tuesday, December 3, 2013 at 12:41pm*

**statistics (?)**

What is your question? If you want to know Kelsey's score: Z = (score-mean)/SD -1.85 = (score-72)/4
*Tuesday, December 3, 2013 at 12:38pm*

**statistics**

poor Kelsey.
*Tuesday, December 3, 2013 at 5:30am*

**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**

mn counting rule
*Tuesday, December 3, 2013 at 3:43am*

**Statistics**

A vending machine is designed to dispense a mean of 7.6 oz. of coffee into an 8-oz cup. If the standard deviation of the amount of coffee dispensed is 0.4 oz. and the amount is normally distributed, find the percent of times that the machine will: a.) Dispense from 7.4 oz. to ...
*Tuesday, December 3, 2013 at 12:02am*

**Statistics**

Dear PsyDAG, Thanks for your help, I suppose the answer to be 17.2 FETs?
*Monday, December 2, 2013 at 9:51pm*

**Statistics**

Dear PsyDAG, Thanks for your help, I suppose the answer to be 17.2 FETs?
*Monday, December 2, 2013 at 9:51pm*

**statistics**

Mean=9 Variance=792 Standard Deviation=28.14
*Monday, December 2, 2013 at 8:54pm*

**statistics**

whether it is one-tailed or two tailed? and if one tailed...I do agree with you now that this is the left tail test. However I am not sure how to handle negative value on t. Here is what I did. I used formula for hypothesis test with mu unknow, t=(xbar-mu)/(sd/sqr n)=(26-25.02...
*Monday, December 2, 2013 at 8:23pm*

**elementary statistics**

There are different ways you can do this kind of problem, but the formula below might be one of the easier ways: s/[1 + (1.645/√2n)] ..to.. s/[1 - (1.645/√2n)] ...where s = standard deviation, 1.645 represents the 90% confidence interval using a z-table, and n = ...
*Monday, December 2, 2013 at 5:42pm*

**Statistics**

1. D Chi Square distributions are positively skewed (skewed to the right). As the degrees of freedom increases, the Chi Square distribution will approach a normal symmetrical distribution. Smaller degrees of freedom will skew more to the right. 2. A Ho: The variables are ...
*Monday, December 2, 2013 at 5:28pm*

**Statistics 2**

Please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time looking over reposts that have already been answered in another post. Thank you. A
*Monday, December 2, 2013 at 12:06pm*

**Statistics**

If the events are independent, the probability of both/all events occurring is determined by multiplying the probabilities of the individual events. 13/52 * 12/51 * 11/50 * 10/49 * (13*3)/48 = ?
*Monday, December 2, 2013 at 12:05pm*

**Statistics**

8600/(100*5) = ?
*Monday, December 2, 2013 at 11:32am*

**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**

Yes. 5% of 300 = 15
*Sunday, December 1, 2013 at 10:28pm*

**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*

**Business Statistics**

Using the telephone numbers listed in your local directory as your population, randomly obtain 20 samples of size 3. From each telephone number identified as a source, take the fourth, fifth, and sixth digits. a. Calculate the mean of the 20 samples b. Draw a histogram showing...
*Sunday, December 1, 2013 at 10:14pm*

**Statistics**

We have a population of all adult women. We take a random sample from this population and create a confidence interval. If we take many, many, many different samples from this population we will obtain many, many, many different sample means and confidence intervals created ...
*Sunday, December 1, 2013 at 9:01pm*

**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 1**

(10+3 +4+ 25 + 1+4+ 4 + 12+ 6 +8 +10)/11 87/11 = 7.9 Answer B
*Sunday, December 1, 2013 at 2:37pm*

**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*

**child care**

This is probably true, although it's just a guess on my part. "Reliable statistics on the prevalence of shaken baby syndrome do not exist. Estimates in the United States approach 50,000 cases each year." http://www.healthline.com/galecontent/shaken-baby-...
*Sunday, December 1, 2013 at 1:48pm*

**statistics**

It is the Z test (google it). Where is your confusion centered?
*Sunday, December 1, 2013 at 12:23pm*

**Math.stat help :(**

Ho: mean1 = mean2 Ha: mean1 ≠ mean2 Since these are just samples rather than the whole population, µ is an inappropriate designation. µ is parameter rather than a statistic. Z = (mean1 - mean2)/standard error (SE) of difference between means SEdiff = √(...
*Sunday, December 1, 2013 at 12:19pm*

**Statistics**

Z = (score-mean)/SD Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.
*Sunday, December 1, 2013 at 12:09pm*

**Probability and Statistics**

Suppose that the antenna lengths of woodlice are approximately normally distributed with a mean of 0.2 inches and a standard deviation of 0.05 inches. What proportion of woodlice have antenna lengths that are more than 0.23 inches? Round your answer to at least four decimal ...
*Sunday, December 1, 2013 at 11:37am*

**Statistics**

1-p(x = 0) + p(x = 1) 1-[(11C0)(.015)^0(.985)^11 + 11C1 *0.015^1 *.985^10)] 1-[.84684 + .14185] 1-.9887 = 0.0113
*Saturday, November 30, 2013 at 11:18pm*

**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**

you're right
*Saturday, November 30, 2013 at 9:45pm*

**Probability and Statistics**

β = P(Type II Error) =P(6≤X ≤13|p=0.5) (0.5)^x(0.5)^15-x ≈ 0.8454 β = P(Type II Error) =P(6≤X ≤13|p=0.7 0.7^x (0.3)^15-x ≈
*Saturday, November 30, 2013 at 9:42pm*

**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*

**math**

Z = (mean1 - mean2)/standard error (SE) of difference between means SEdiff = √(SEmean1^2 + SEmean2^2) SEm = SD/√n If only one SD is provided, you can use just that to determine SEdiff. Find table in the back of your statistics text labeled something like "...
*Saturday, November 30, 2013 at 4:26pm*

**statistics**

what test are you using? This is very confusing!
*Saturday, November 30, 2013 at 1:20pm*

**statistics**

Z = (mean1 - mean2)/standard error (SE) of difference between means SEdiff = √(SEmean1^2 + SEmean2^2) SEm = SD/√n (n = # of trips) If only one SD is provided, you can use just that to determine SEdiff. Find table in the back of your statistics text labeled ...
*Saturday, November 30, 2013 at 12:53pm*

**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*

**Statistics**

a
*Saturday, November 30, 2013 at 10:23am*

**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**

Thank you, I got the same answer, but I thought that because the sample size was less than 30, there was something I missed.
*Friday, November 29, 2013 at 11:30pm*

**Statistics**

mean = $115 Sd = $25 n = 15 1-a = .92 a = 0.08 Za/2 = z.04 = 1.75 115 -+ 1.75 * 25/sqrt15)) 115-+ 11.296 (103.704, 126.296)
*Friday, November 29, 2013 at 11:25pm*

**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**

raw numbers
*Friday, November 29, 2013 at 8:55am*

**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**

KE$HA IS A CELEB. I LOVE HER I LOV EHER KE$HIE IS A CELEB I LOVE HER_♥__♥_____♥__♥;___ Put This _♥_____♥_♥_____♥__ Heart _♥______♥______♥__ On Your __♥_____/______♥__ Page If ___♥...
*Wednesday, November 27, 2013 at 1:14pm*

**Math**

I'm currently taking IBMS and it has elements of several types of math classes (calculus, statistics, algebra, etc.). It is the "lowest" level IB Math class one can take, but not necessarily for students who have a low background in math. I know one student who ...
*Wednesday, November 27, 2013 at 10:45am*

**Statistics**

well, since 51.75 is 57.5% of the way between 46 and 56, ...
*Wednesday, November 27, 2013 at 6:05am*

**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. Ho: p = 0.5 Ha: p > 0.5 b) z = 2.41 c) p-value = 0.0080 d) reject the Ho; there is sufficient evidence to claim that the probability of a baby being a girl is greater than 0.5
*Tuesday, November 26, 2013 at 6:27pm*

**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 few hints: If you use the normal distribution as an approximation, then you will need to find the mean and standard deviation. mean = np = 13 * 0.7 = 9.1 standard deviation = √npq = √(13)(0.7)(0.3) = 1.65 (rounded) Note: q = 1 - p Next step: use z-scores z = (x...
*Tuesday, November 26, 2013 at 4:41pm*

**statistics**

The result is a statistic because it describes some characteristics of a sample. Or is it because if describes some characteristics of a population? this is where I get confused. thanks
*Tuesday, November 26, 2013 at 1:37pm*

**statistics**

A parameter is data about the whole population, while a statistic deals with a part of the population, a sample. What does that tell you?
*Tuesday, November 26, 2013 at 1:16pm*

**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**

See your other post.
*Monday, November 25, 2013 at 7:24pm*

**statistics**

Outliers in a box plot may be evidence of a non-normal distribution, but this might not always be the case. If the box plot has symmetry around the median, the distribution will most likely be normal.
*Monday, November 25, 2013 at 7:23pm*

**Statistics**

It may be due to the sample size. There is a possibility the sample may be too large, which will affect the significance of the outcome.
*Monday, November 25, 2013 at 6:51pm*

**statistics**

You can try a proportional one-sample z-test for this one since this problem is using proportions. Here's a few hints to get you started: Null hypothesis: Ho: p = .5 -->meaning: population proportion is equal to .5 Alternative hypothesis: Ha: p > .5 -->meaning: ...
*Monday, November 25, 2013 at 6:36pm*

**statistics**

If you need to show the work by hand, you can develop the regression equation in the following format: predicted y = a + bx ...where a represents the y-intercept and b the slope. To get to that point, here are some formulas to calculate along the way. To find a: a = (Ey/n) - b...
*Monday, November 25, 2013 at 6:25pm*

**Statistics**

If you perform a statistical test, try a one-sample z-test. z = (sample mean - population mean)/(standard deviation divided by the square root of the sample size) Population mean = 80 Sample mean = ? (I don't see one listed) Standard deviation = 10.15 Sample size = 50 Once...
*Monday, November 25, 2013 at 6:19pm*

**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**

right.
*Monday, November 25, 2013 at 1:26pm*

**Statistics**

% = mean ± Z(SEm) Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability (%/2) from the mean and its Z score. Substitute values into above equation and calculate. If you ...
*Monday, November 25, 2013 at 1:23pm*

**statistics**

A normal distribution approximates a bell-shaped curve. Outliers to one side would skew the distribution. If the distribution was flat, having about the same frequencies throughout the distribution, this would be non-normal. Also a bimodal distribution would be non-normal, ...
*Monday, November 25, 2013 at 1:17pm*

**statistics psy/315**

Z = (mean1 - mean2)/standard error (SE) of difference between means SEdiff = √(SEmean1^2 + SEmean2^2) SEm = SD/√n If only one SD is provided, you can use just that to determine SEdiff. Find table in the back of your statistics text labeled something like "...
*Monday, November 25, 2013 at 1:02pm*

**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**

(1.96*2.5)/0.25)^2=384.16 that's right or wrong?? i'm not understand why the population standard deviation round up to 3?? anyone help? this for question post by shyra..
*Monday, November 25, 2013 at 1:27am*

**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**

I think I have it...nevermind .94 on z chart =1.55...then multiply 1.55 times error (10) then time 60=75.5?
*Sunday, November 24, 2013 at 5:26pm*

**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*

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