Exam 12: Chi-Square Tests

In performing a chi-square goodness-of-fit test for a normal distribution,if there are 7 intervals,then the degrees of freedom for the chi-square statistic is ______________.

Expected cell frequencies for a multinomial distribution are calculated by assuming statistical dependence.

When we carry out a chi-square test of independence,as the differences between the respective observed and expected frequencies decrease,the probability of concluding that the row variable is independent of the column variable:

The AAA Co.is interested in the level of satisfaction of their employees in the benefit package that they offer compared to their major competitors.A consultant hired to conduct the satisfaction survey told AAA Co.that the distribution of level of satisfaction at other companies is displayed below: A survey was conducted of 125 AAA employees with the following results: Using the critical value for α = .05,test the null hypothesis that the distribution of AAA employees at each satisfaction level is similar to the distribution of the employees of their major competitors.

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: State the null hypothesis that states the expectations of the auditors.

A multinomial probability distribution describes data that are classified into two or more categories when a multinomial experiment is carried out.

In performing a chi-square test of independence,as the difference between the respective observed and expected frequencies decreases,the probability of concluding that the row variable is independent of the column variable decreases.

On the most recent tax cut proposal,a random sample of Democrats and Republicans in the Congress cast their votes as follows: At a significance level of .01,determine the appropriate degrees of freedom and the rejection point condition for this test.

A manufacturing company produces part A732 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 A732 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. Chi-Square Contingency Table Test for Independence At a significance level of .05,the management wants to perform a hypothesis test to determine if the quality of the items produced appears to be independent of the production process used.Based on the results summarized in the MegaStat/Excel output provided in the table above,we:

The AAA Co.is interested in the level of satisfaction of their employees with the benefit package that they offer compared to their major competitors.A consultant hired to conduct the satisfaction survey told AAA Co.that the distribution of level of satisfaction at other companies is displayed below: A survey was conducted of 125 AAA employees with the following results: What are the degrees of freedom for testing the goodness of fit at α = .05?

When we carry out a chi-square test of independence,the expected frequencies are based on the null hypothesis.

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.

Consider a set of 50 measurements with mean 50.2 and standard deviation 18.7 and with the following observed and expected frequencies. It is desired to test whether these measurements came from a normal population.At a significance level of .05,test H₀: the set of 50 measurements came from a normal population.

Consider the 3 × 2 contingency table below. Compute the expected frequencies in row 2.

The number of degrees of freedom associated with a chi-square test for independence based upon a contingency table with 4 rows and 3 columns is _____.

The HR manager of a major office supply chain is interested in determining whether employee educational level affects knowledge of their job.An exam was given to 120 employees.The results are below: For each row total,calculate the corresponding percentage.

In performing a chi-square goodness-of-fit test with multinomial probabilities,the smaller the difference between observed and expected frequencies,the higher the probability of concluding that the probabilities specified in the null hypothesis are correct.

One use of the chi-square goodness-of-fit test is to determine if specified multinomial probabilities in the null hypothesis are correct.

The following frequency table summarizes the ages of 60 shoppers at the local grocery store. 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.

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 _____.