Exam 12: Experimental Design and Analysis of Variance

When we carry out a chi-square goodness-of-fit test for a normal distribution,the null hypothesis states that the population

A study of car accidents and drivers who use cell phones collects the following sample data. Determine the expected frequencies of those who had accidents in the last year to use for the chi-square test of independence.

When we carry out a chi-square test of independence,in the alternative hypothesis we state that the two classifications are statistically independent.

A special version of the chi-square goodness-of-fit test that involves testing the null hypothesis that all of the multinomial probabilities are equal is called the test for ___________.

A paper presented at a recent meeting of higher education researchers compared the type of college freshmen attend and the numbers who drop out.A random sample of freshmen shows the following results. Calculate the chi-square statistic for this test of independence.

A survey was conducted on the age and gender of the purchasers of a specific automotive model.The results are below. For each column total,calculate the corresponding percentage.

A real estate company is analyzing the selling prices of residential homes in a given community.140 homes that have been sold in the past month are randomly selected and their selling prices are recorded.The statistician working on the project has stated that in order to perform various statistical tests,the data must be distributed according to a normal distribution.In order to determine whether the selling prices of homes included in the random sample are normally distributed,the statistician divides the data into 6 classes of equal size and records the number of observations in each class.She then performs a chi-square goodness-of-fit test for normal distribution.The results are summarized in the following table. At a significance level of .05,what is the appropriate rejection point condition?

The chi-square distribution is a continuous probability distribution that is skewed to the left.

A manufacturing company produces part QV2Y for the aerospace industry.This particular part can be manufactured using 3 different production processes.The management wants to know if the quality of the units of part QV2Y is the same for all three processes.The production supervisor obtained the following data: Process 1 had 29 defective units in 240 items,Process 2 produced 12 defective units in 180 items,and Process 3 manufactured 9 defective units in 150 items.At a significance level of .05,we performed a chi-square test of independence to determine if the quality of the items produced appears to be independent of the production process.What are the degrees of freedom for the chi-square statistic?

The following frequency table summarizes the ages of 60 shoppers at the local farmer's market. The estimated mean is 36.25,and the estimated standard deviation is 13.57.Calculate the expected frequencies for each interval,assuming a normal distribution.

AAA Co.operates distribution centers in the Midwest.Three of their centers were recently audited to determine if they are in compliance with company standard billing procedures.According to the auditing firm,a billing had an equal probability of being from each of the three centers.A random sample of the audited billings had the following distribution.Center 1: 385 billings Center 2: 305 billings Center 3: 210 billings What are the degrees of freedom for the χ² test?

The χ² goodness-of-fit test requires the nominative level of data.

An experiment consists of 400 observations and four mutually exclusive groups.If the probability of a randomly selected item being classified into any of the four groups is equal,then the expected number of items that will be classified into group 1 is _____.

A real estate company is analyzing the selling prices of residential homes in a given community.140 homes that have been sold in the past month are randomly selected and their selling prices are recorded.The statistician working on the project has stated that in order to perform various statistical tests,the data must be distributed according to a normal distribution.In order to determine whether the selling prices of homes included in the random sample are normally distributed,the statistician divides the data into 6 classes of equal size and records the number of observations in each class.She then performs a chi-square goodness-of-fit test for normal distribution.The results are summarized in the following table. At a significance level of .05,we

When using the chi-square goodness-of-fit test,if the value of the chi-square statistic is large enough,we reject the null hypothesis.

The trials of a multinomial probability are assumed to be dependent.

Which,if any,of the following statements about the chi-square test of independence is false?

The following frequency table summarizes the ages of 60 shoppers at the local farmer's market. The estimated mean is 36.25,and the estimated standard deviation is 13.57.Calculate the value of the chi-square test statistic to determine whether these measurements came from a normal population. χ² = (10 − .24)²/.24 + (21 − 22.458)²/22.458 + (10 − 15.51)²/15.51 + (8 − 12.27)²/12.27 + (5 − 6.732)²/6.732 + (6 − 2.79)²/2.79 = 404.58

AAA Co.operates distribution centers in the Midwest.Three of their centers were recently audited to determine if they are in compliance with company standard billing procedures.According to the auditing firm,a billing had an equal probability of being from each of the three centers.A random sample of the audited billings had the following distribution.Center 1: 385 billings Center 2: 305 billings Center 3: 210 billings What is the expected value of the number of billings for each center if H₀ (equal probabilities)is true?

A survey was conducted on the age and gender of the purchasers of a specific automotive model.The results are below. For each cell,calculate the corresponding cell,row,and column percentage.