Monday

July 25, 2016
**statistics, probability**

It has been found out that the probability that a child is a male in family is 0.4. In a family of 6 children, what is the probability that; i. exactly 5 are boys ? ii. at least 4 are boys ? iii. all boys
*Wednesday, July 9, 2014 by pauline*

**Statistics**

The life of an electric light bulb is known to be normally distributed with a mean of 2000 hours and a std. of 120 hours. Find the probability that the life of such a bulb would be. (a) greater than 2150 hours (b) within the range of 1850 hours to 2090 hours
*Tuesday, July 8, 2014 by Heidi*

**Math (statistics)**

In an examination a candidate is given the four answers to four questions but is not told which answer applies to which question. He is asked to write down each of the four answers next to its appropriate question. b). show that there are 6 ways of getting just two answers in ...
*Tuesday, July 8, 2014 by Heidi*

**statistics**

What formula do I use to solve: A sample with a mean of M = 40 and a variance of s2 = 20 has an estimated standard error of 2 points. How many scores are in the sample?
*Tuesday, July 8, 2014 by brenda*

**statistics**

A teacher wants to compare the mean geology scores of two different classes. She is testing the null hypothesis that there is no difference in the population mean scores of the two classes. The difference of the sample means is 51.4. If the standard deviation of the ...
*Monday, July 7, 2014 by bobert*

**Math/Statistics**

A group of 10 students have average of GPA of 2.8 with SD of 0.3. Does this group present enough evidence to indicate that the average GPA is less than 3.0? Make your decision at a 5% level of significance.
*Monday, July 7, 2014 by Anonymous*

**Statistics**

A group of 10 students have average of GPA of 2.8 with SD of 0.3. Does this group present enough evidence to indicate that the average GPA is less than 3.0? Make your decision at a 5% level of significance
*Monday, July 7, 2014 by Walkira*

**statistics**

Twelve different video games showing substance use were observed and the duration times of game play (in seconds) are listed below. The design of the study justifies the assumption that the sample can be treated as a simple random sample. Use the sample data to construct and ...
*Monday, July 7, 2014 by Teniqua Evans*

**statistics**

Could someone let me know if I did this correctly? Source Sum of Squares (degrees of freedom [df]) Mean Square Fobt. Fcrit. Gender 68.15 1.07 68.15/63.685 0.59 1.07,1,2 Marital Status 127.37 3.04 63.685/20.95 0.75 3.04,2,2 Gender * Marital Status (A x B) 41.90 2.28 20.95/9.2 0...
*Monday, July 7, 2014 by Kim*

**statistics**

As a marketing promotion a company is going to give the first 200 customers a coupon for a discount when they enter the store. The customer cannot scratch off the coupon until they check out. the company orders 200 coupons and 150 are for 5% off, 30 are for 10% off, 15 are for...
*Monday, July 7, 2014 by anne*

**statistics**

Describe one of the following experiments, which study human subjects, in 450 to 750 words: A pharmaceutical company wants to test a new sleep aid. An educational company is interested in determining whether their new math curriculum will raise standardized test scores. ...
*Sunday, July 6, 2014 by Anonymous*

**statistics**

If you are told the mean grade in ECON 2023 is 80 with a standard deviation of 5, what is the probability that if you randomly selected 36 students you would find an average grade of 82 or more? I found the Z-score: 82-80/5 Which gave me .6554 then 1-.6554=.3446 So 34% would ...
*Sunday, July 6, 2014 by Colby*

**statistics**

Blood type AB is found in only 3% of the population†. If 240 people are chosen at random, find the probability of the following. (Round your answers to four decimal places.) (a) 5 or more will have this blood type (b)between 5 an 10 will have this blood type
*Saturday, July 5, 2014 by tc*

**Math**

Statistics show that the sales force of a certain company successfully closed 296 sales out of 800 sales calls. What was their percent success rate?
*Friday, July 4, 2014 by Diana*

**Statistics**

If a couple has 4 children and none are from multiple births or twins. With the probability of sons being 50% how many sons would they expect to have?
*Friday, July 4, 2014 by Denise*

**Statistics**

The mean score on the first calculus exam was 55%. The standard deviation was 7%. Find the smallest interval about the mean that must contain at least 83% of the scores. heeellllppppp
*Friday, July 4, 2014 by jack higgins*

**statistics**

At the start of December 2001, the retail price of a 25kg bag of cornmeal was $10 in Zambia, while by the end of the month, the price had fallen to $6. The result was that one retailer reported an increase in sales from 3 bags/day to 5 bags/day. Assume that the retailer is ...
*Thursday, July 3, 2014 by Jody*

**statistics**

in november 2008, apple stock dropped from $105 to $95 per share, and Microsoft dropped from $21 to $20 per share. If you invested a total of $3,570 in these stocks at the end of October and sold them for $3,250 at the end of November, how many shares of each stock did you buy?
*Thursday, July 3, 2014 by Jody*

**statistics**

help! where do i begin with this problem...in one area, monthly incomes of technology related workers have a standard deviation of $650. It is believed that the standard deviation of monthly incomes of non-technology workers is higher. A sample of 71 non technology workers are...
*Tuesday, July 1, 2014 by carmen*

**statistics**

how much sale tax in due for a payment of 993.91
*Tuesday, July 1, 2014 by jennifer*

**statistics**

One of the ways most people relieve stress is to reward themselves with sweets. According to one study in Food Technology, 46 percent admit to overeating sweet foods when stressed. Suppose that the 46 percent figure is correct and that a random sample of 100 people is selected...
*Tuesday, July 1, 2014 by Alfie*

**Statistics **

Compute the critical value za/2 that corresponds to a 85% level of confidence.
*Monday, June 30, 2014 by Kasey*

**Statistics **

An investor has $1400 to invest, and his financial analyst recommends two types of junk bonds. The A bonds have a 6% annual yield with a default rate of 3%. The B bonds have a 9% annual yield with a default rate of 7%. (If the bond defaults, the $1400 is lost.) Which of the ...
*Monday, June 30, 2014 by Kasey*

**Statistics**

A statistics professor plans classes so carefully that the lengths of her classes are uniformly distributed between 50.0 and 52.0 minutes. Find the probability that a given class period runs between 50.25 and 50.5 minutes.
*Monday, June 30, 2014 by Kasey*

**Statistics**

Many states are carefully considering steps that would help them collect sales taxes on items purchased through the Internet. How many randomly selected sales transactions must be surveyed to determine the percentage that transpired over the Internet? Assume that we want to be...
*Monday, June 30, 2014 by Kasey*

**statistics**

A Gallup poll of 1236 adults showed that 12% of the respondents believe that it is bad luck to walk under a ladder. Consider the probability that among 30 randomly selected people from 1236 who were polled, there are at least 2 who have that belief. Given that the subjects ...
*Monday, June 30, 2014 by Kasey*

**Statistics**

Find the critical value za/2 that corresponds to the given confidence level. 96%
*Monday, June 30, 2014 by Kasey*

**Statistics**

Assume that a procedure yields a binomial distribution with a trial repeated n times. Use the binomial probability formula to find the probability of x successes given the probability p of success on a single trial. n=21, x=18, p=0.75
*Monday, June 30, 2014 by Kasey*

**Statistics**

The distribution of IQ scores is a nonstandard normal distribution with a mean of 100 and a standard deviation of 15. What are the value of the mean and standard deviation after all IQ score have been standardized by converting them to z scores?
*Monday, June 30, 2014 by Kasey*

**Statistics**

Find the critical values x2L and x2R that correspond to the given confidence level and sample size. 99%: n=23
*Monday, June 30, 2014 by Kasey*

**statistics**

Assume that a procedure yields a binomial distribution with a trial repeated n times. Use a binomial probabilities table to find the probability of x successes given the probability p of success on a given trial. n=8, x=2, p=0.30
*Monday, June 30, 2014 by Kasey*

**Statistics**

A clinical trial tests a method designed to increase the probability of conceiving a girl. In the study 320 babies were born, and 256 of them were girls. Use the sample data to construct a 99% confidence interval estimate of the percentage of girls born. Based on the results, ...
*Monday, June 30, 2014 by Kasey*

**statistics**

simple randon sampling uses a sample size n
*Monday, June 30, 2014 by Anonymous*

**Statistics**

An unbiased die is thrown seven times. Find the probability of throwing it at least five six's.
*Monday, June 30, 2014 by Heidi*

**statistics**

Select which of the following are examples of parameters from these examples. Question options: The probability that a ticket with be a winner is .2 (or a 20% chance) The proportion of winning tickets in the sample of 100 99% of samples will have between 37% and 43% of voters ...
*Sunday, June 29, 2014 by Anonymous*

**statistics**

use SPSS to calculate the 90%, 95% and 99% confidence intervals for the mean of the variable weight. Interpret the three confidence intervals in terms of whether there is a significant difference between the mean of the sample and a hypothesized mean of 150.
*Sunday, June 29, 2014 by love*

**statistics**

The inside diameter of metal washers produced by a company are normally distributed with a mean of .5 inches and a standdrd deviation of .01 inches. Of all washers produced .8% of the washers are rejected because they are too small for a bolt used to test them. What is the ...
*Saturday, June 28, 2014 by josh*

**statistics**

To find out what people think, the Gallup Poll selected a random sample of 520 women and 506 men. The pollsters showed them a list of personal attributes and asked them to indicate whether each attribute was “generally more true of men or of women”. When asked about ...
*Friday, June 27, 2014 by Devin*

**statistics**

2. A researcher measures the heart rate in a population of runners and finds they have an average heart rate of µ = 50, σ = 5. You do not need to show a graph, only computation work. 2A. Based on the average heart rate cited above, what proportion would we expect to...
*Friday, June 27, 2014 by chris*

**statistics**

construct a 95% confidence interval estimate for the population mean MPG of 2010 family sedans, assuming a normal distribution.
*Friday, June 27, 2014 by lou*

**Statistics (Check Work)**

Can Someone help me with these 2 problems? I am certain I am solving them correctly, but for some reason the computer keeps marking my answers as incorrect. Question 1: Minnesota had the highest turnout rate of any state for the 2012 Presidential election. Political analysts ...
*Thursday, June 26, 2014 by Jen*

**Statistics**

1. In a study of heart disease in male federal employees, researchers classified 170 volunteer subjects according to their socioeconomic status (SES) and their smoking habits. SES categorized as high and low. Individuals were asked whether they were smokers or non-smoker. Here...
*Thursday, June 26, 2014 by MT*

**statistics**

A sample of 40 CDs from a student's collection showed a mean length of 52.74 minutes with a standard deviation of 13.21 minutes. Construct a 95% confidence interval for the population standard deviation. (Round your answers to 4 decimal places.)
*Thursday, June 26, 2014 by Anonymous*

**statistics**

Facebook reports that the average number of Facebook friends worldwide is 150 with a standard deviation of 90. If you were to take a sample of 25 students, what is the probability that the mean number Facebook friends in the sample will be 165 friends or more?
*Tuesday, June 24, 2014 by Anonymous*

**statistics**

according to statistics, the maximum heart rate should be 220 minus a person's age. how would you interpret your highest rate in relation to that given?
*Tuesday, June 24, 2014 by jovelyn*

**Statistics**

No idea where to begin... Do men or women watch more T.V. per day? To answer the question two samples were select with the help of SPSS and the following results were produced. Is there a significant difference between men and women in watching T.V.? Perform five-step model to...
*Sunday, June 22, 2014 by Suzanne*

**Statistics**

I'm taking stats online which is making it even more difficult for me and I have nowhere to begin when answering this question. 1. A pharmaceutical industry claimed that their new product will lower the cholesterol level by an average of 14.5. To verify the claim, a ...
*Sunday, June 22, 2014 by Michelle*

**statistics**

The following random sample was collected: 22 33 44 6. The 80% confidence interval for the mean is? I have the answers; however, I do not know how to plug in the numbers to solve the problem.
*Saturday, June 21, 2014 by Nicole*

**statistics **

A researcher wishes to estimate the proportion of college students who cheat on exams. A poll of 490 college students showed that 33% of them had, or intended to, cheat on examinations. Find the margin of error for the 95% confidence interval. solution I have but what do I ...
*Thursday, June 19, 2014 by Lucky Lady*

**probability and statistics**

Suppose every student in your class got a score of 85% on an exam. What are the mean and standard deviation of those exam scores without doing any calculations? I want to say the mean is 100 and the standard deviation is 1 but I don't know why. If all students scored 85% ...
*Tuesday, June 17, 2014 by Tiffany*

**Statistics**

there is a 1/5 (.20) probability that one type of appliance will break with in two years. find the probability that 4 out 15 such appliances willl break within that time period
*Tuesday, June 17, 2014 by Anonymous*

**statistics**

The true highway mileage, Y, of a specific brand of hybrid vehicle has a normal distribution with a mean of 42 and a standard deviation of 1.5. Find the probability that a randomly selected hybrid vehicle gets more than 38 miles to the gallon.
*Tuesday, June 17, 2014 by lisa*

**Statistics**

One of the questions in the Pew Internet & American Life Project asked adults if they used the Internet, at least occasionally. The results showed that 454 out of 478 adults aged 18 - 29 answered yes; 741 out of 833 adults aged 30 – 49 answered yes; 1058 out of 1644 ...
*Monday, June 16, 2014 by Jen*

**Statistics (Check Answer)**

Hi can someone check my answer. I'm not sure why the computer keeps marking it wrong. **Suppose a random sample of size 50 is selected from a population with σ = 10. Find the value of the standard error of the mean in each of the following cases (use the finite ...
*Monday, June 16, 2014 by Jen*

**statistics for health research**

1.A study is conducted to determine the factors that affect the increased maternal mortality rates in Kenya. Establish the variables (at least 5 variables) that you would use to conduct the study. State your expected results and explain how you will apply Correlation and ...
*Monday, June 16, 2014 by maureen*

**statistics for health research**

Descriptive statistics are widely used in qualitative research. When establishing if a population is normally distributed explain when the statistics of sample size, mean, mode, median, skewness and kurtosis will guide the researcher to make conclusions of a normal distribution.
*Monday, June 16, 2014 by maureen*

**statistics for health research**

the income of a group of 10,000 health system employees was found to be normally distributed with a mean=750 pm and standard deviation=50. show that of this group about 95% had income exceeding 668 and only 5% had income exceeding 832
*Monday, June 16, 2014 by maureen*

**Statistics**

Assume that a standardized test is designed to have the mean score of 100 and the standard deviation of 15. At the 95% confidence interval, how large does the sample size have to be if the margin of error is to be 3 points?
*Sunday, June 15, 2014 by Anonymous*

**statistics**

A graph representing the distribution of the oral temperatures of 50 healthy adult males (selected at random) would best be described as?
*Sunday, June 15, 2014 by ally*

**math statistics**

In a survey of families in which both parents work, one of the questions asked was, "Have you refused a job, promotion, or transfer because it would mean less time with your family?" A total of 200 men and 200 women were asked this question. "Yes" was the ...
*Saturday, June 14, 2014 by stumped*

**Statistics**

The complement of P(B | A) is 1 - P(B | A). Is it also true that 1 - P(B | A) = P(B' | A), where B' means the complement of B?
*Friday, June 13, 2014 by John*

**Statistics**

You have these 10 observations of some event X: 1.03 1.022 1.022 1.01 1.026 1.02 0.95 1.005 1.05 1.023 Here is the sorted list from least to greatest: 0.95 1.005 1.01 1.02 1.022 1.022 1.023 1.026 1.03 1.05 Based on this data alone: 1) It makes sense to say P(X <= 0.95) = 1/...
*Thursday, June 12, 2014 by Bob*

**statistics**

Assume that a standardized test is designed to have the mean score of 100 and the standard deviation of 15. At the 95% confidence interval, how large does the sample size have to be if the margin of error is to be 3 points?
*Thursday, June 12, 2014 by virginia*

**Statistics **

A research worker wishes to estimate the mean of a population by using sufficiently large sample. At the confidence level of 99%,the sample mean will be within 35% of the standard deviation. How large a sample should be taken?
*Wednesday, June 11, 2014 by Brandon*

**Statistics**

The mean cost of domestic airfares in the United States rose to an all-time high of $385 per ticket. Airfares were based on the total ticket value, which consisted of the price charged by the airlines plus any additional taxes and fees. Assume domestic airfares are normally ...
*Wednesday, June 11, 2014 by Sam*

**statistics**

A politician claims that she will receive 65% of the vote in an upcoming election. The results of a properly designed random sample of 100 voters showed that 49 of those sampled will vote for her. Is it likely that her assertion is correct at the 0.05 level of significance? (a...
*Wednesday, June 11, 2014 by confused*

**statistics**

in a class of 100,84% of student have taken politics and 16% of the students have taken history. how many students have taken both subject of all the students take at least one these students?
*Wednesday, June 11, 2014 by satyam*

**Statistics**

Can someone please help me answer these questions? I have tried every method I know and the computer still keeps marking the answers as incorrect. Thanks for the help! 1) If the number of 18-34 year olds sampled is equal to the value identified in part "a"(value=157...
*Tuesday, June 10, 2014 by Jen*

**Statistics**

How would you interpret the findings of a correlation study that reported a linear correlation of +0.3? I believe they have nothing in common because they are close to one. Please advise
*Tuesday, June 10, 2014 by Chevelle DuBois*

**math, statistics**

The image of the public library is constantly changing, and their online services continue to grow. Usage of the library's home page grew by 17% during the past 12 months. It has been estimated that the current average length of a visit to the library's homepage is ...
*Tuesday, June 10, 2014 by BJ*

**civics**

statistics show that internet usage in the United states has grown from just 41 percent of households in 2000 to 77 present household in 2012. Which best describes how the internet has contributed to cultural diffusion in the United states? I'm stuck I don't even have ...
*Tuesday, June 10, 2014 by Help!!! Mrs sue*

**statistics**

For a normal distribution, explain why we calculate the probability of a range of numbers instead of the probability of a single number on the lines below?
*Monday, June 9, 2014 by rehena *

**statistics**

What is the null hypothesis for the following questions: Is there a relationship between heart rate and the number of cups of coffee drunk within the last 4 hours?
*Monday, June 9, 2014 by lachon*

**statistics**

An investigator wants to estimate caffeine consumption in high school students. How many students would be required to estimate the proportion of students who consume coffee? Suppose we want the estimate to be within 5% of the true proportion with 95% confidence. Alpha = ...
*Sunday, June 8, 2014 by Yvette*

**Math statistics**

How large a sample should be taken if the population mean is to be estimated with 95% confidence to within $69? The population has a standard deviation of $892. (Round you answer up to the nearest whole number.) You may need to use the appropriate table in Appendix B to answer...
*Sunday, June 8, 2014 by hanjay*

**Math, statistics**

A trucking firm delivers appliances for a large retail operation. The packages (or crates) have a mean weight of 306 lb. and a variance of 2209. (Give your answers correct to four decimal places.) (a) If a truck can carry 4070 lb. and 25 appliances need to be picked up, what ...
*Sunday, June 8, 2014 by hanjay*

**statistics**

company A has 110 employed, company B has 750 employed and company C has 250 employed. Compute the probability that an employee selected at random comes from company A or B.
*Saturday, June 7, 2014 by iris*

**statistics**

The outcome of a standardized test is an integer between 151 and 200, inclusive. The percentiles of 400 test scores are calculated, and the scores are divided into corresponding percentile groups. Quantity A Minimum number of integers between 151 and 200, inclusive, that ...
*Saturday, June 7, 2014 by faysakelahi*

**statistics**

300 test results are integers ranging from 15 to 75, inclusive. Dominick’s result is clearly in the 80th percentile of those results, not the 79th or the 81st. Quantity A Number of other test results in the same percentile as Dominick’s Quantity B Maximum number of ...
*Saturday, June 7, 2014 by faysakelahi*

**statistics**

solve: our health organization is interested in estimating the average value of outstanding accounts receivable. After selecting a sample of 100 accounts, suppose that the mean was $120 and the standard deviation was $40. Use these data to construct a 98% confidence interval. ...
*Friday, June 6, 2014 by Winona*

**Statistics **

The life of a blood pressure monitor has a normal distribution with an average of 40 years and a standard deviation of one year. What should the warranty be to replace a malfunctioning monitor with - if the company does not want to replace more than 1% of all the monitor. ...
*Friday, June 6, 2014 by Ann*

**Statistics**

The registration numbers of vehicles in a certain country use digits 1-999. If a visitor has just entered the country. What is the probability that the first car he sees has at least 2 identical digits? Ans: 29/111
*Friday, June 6, 2014 by Ariana*

**math**

A sample of 64 statistics students at a small college had a mean mathematics ACT score of 28 with standard deviation of 4. Estimate the mean mathematics ACT score for all statistics students at college. Give the 95% confidence interval.
*Thursday, June 5, 2014 by Erma*

**statistics**

What are the differences between hypothesis testing regarding population means drawn from small and large samples
*Thursday, June 5, 2014 by Sam *

**STATISTICS**

Suppose that you are in a class of 29 students and it is assumed that approximately 16% of the population is left-handed. (Give your answers correct to three decimal places.) (a) Compute the probability that exactly five students are left-handed. (b) Compute the probability ...
*Thursday, June 5, 2014 by BJ*

**statistics**

suppose you roll two number cubes and pick a letter of the alphabet at random. find the probability you will roll two odd numbers and pick one of the letters k, l, or m.
*Wednesday, June 4, 2014 by logan*

**statistics**

The diameter of an electric cable is normally distributed, with a mean of 0.6 inch and a standard deviation of 0.02 inch. What is the probability that the diameter will exceed 0.62 inch? (You may need to use the standard normal distribution table.
*Wednesday, June 4, 2014 by leelee kay *

**statistics**

Draw a stem-and-leaf plot for the data set. (Enter numbers from smallest to largest separated by spaces. Enter NONE for stems with no values.) 60 14 24 35 22 37 14 23 19 33 15 16 50
*Tuesday, June 3, 2014 by leelee kay *

**statistics**

the breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 125 and a variance of 25. The material is considered defective if the breaking strength is less than 113 pounds. What is the probability that a single, randomly selected piece ...
*Tuesday, June 3, 2014 by leelee kay *

**statistics**

the breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 125 and a variance of 25. The material is considered defective if the breaking strength is less than 113 pounds. What is the probability that a single, randomly selected piece ...
*Tuesday, June 3, 2014 by Anonymous*

**statistics**

Between 50 and 80 people are hired on a ship. 75% speak English only and 25% speak German only. What is the mean number of people that speak English only? Can this even be calculated?
*Tuesday, June 3, 2014 by Pete*

**statistics**

In how many ways can 24 identical white ball and 19 black ball be arranged in rows so that no black balls are together.
*Tuesday, June 3, 2014 by roma*

**statistics**

In a class of 100 ,84% of the students have taken politics &16% of student have taken history.how many students have taken both subject of all the students take at least one of these subjects?
*Tuesday, June 3, 2014 by roma*

**statistics**

An 8th grade history teached studied the statistics for her mid-term exam. The average grade for the mid-term was 84 points, and the standard deviation was 8 points. The Z-score for a student who scores 90 on the exam is: 84-90/8= -0.75
*Tuesday, June 3, 2014 by Jodi *

**statistics**

Give the probability in decimal form (correct to two decimal places). A calculator may be helpful. Last semester, a certain professor gave 35 As out of 259 grades. If one of the professor's students from last semester were selected randomly, what is the probability that ...
*Sunday, June 1, 2014 by ALIS*

**Statistics/I am confused**

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 115 and a variance of 25. The material is considered defective if the breaking strength is less than 105 pounds. What is the probability that a single, randomly selected piece ...
*Saturday, May 31, 2014 by Mary Ann *

**statistics**

A sample of n= 4 scores has SS equals 48 what is the estimated standard error for the sample mean
*Saturday, May 31, 2014 by Jamie*

**Statistics**

A class obtained the following scores on a test. Test Score TestScore Frequency 90 1 80 6 70 10 60 3 50 2 40 3 What I did was 90+6(80)+7(10)+3(60)+2(50)+3(40)=1040 than divided by 25 which should give me the means it give me a fraction, I got the median right 70,mode right 70...
*Saturday, May 31, 2014 by Mary Ann *

**Statistics/ is this how I do it.**

Find the range and the standard deviation (correct to two decimal places). 83,96,100,100,103 find the range and standard deviation Do I that 5 numbers add that divide by 5 for the range I am not sure how to do standard deviation. Thank you
*Saturday, May 31, 2014 by Mary Ann *

**Statistics 1**

If light bulbs are normally distributed with a mean of 2500 hrs. and a standard deviation of 500 hrs. what percentage of light bulbs have a life span less than 2500 hrs.?
*Friday, May 30, 2014 by Tom gordy*