Exam 15: Chi-Squared Tests

The expected values of a contingency table are calculated based on the assumption that H₀ is ____________________.

In 2011,the student body of a state university in Alabama consists of 30% freshmen,25% sophomores,27% juniors,and 18% seniors.A sample of 400 students taken from the 2012 student body showed that there are 138 freshmen,88 sophomores,94 juniors,and 80 seniors.Test with 5% significance level to determine whether the student body proportions have changed.

A multinomial experiment with two categories is identical to a binomial experiment.

Which of the following tests is appropriate for nominal data if the problem objective is to compare two or more populations and the number of categories is at least 2?

Which of the following tests is used to analyze nominal data?

The following data are believed to have come from a normal probability distribution. 26 21 25 20 21 29 26 23 22 24 24 30 23 32 26 24 32 16 36 26 21 31 26 23 32 35 40 30 14 26 46 27 33 25 27 21 26 18 29 36 The mean of this sample equals 26.80,and the standard deviation equals 6.378.Use the goodness-of-fit test at the 5% significance level to test whether the data indeed come from a normal distribution.

Student Absenteeism Consider a multinomial experiment involving n = 200 students of a large high school.The attendance department recorded the number of students who were absent during the weekdays.The null hypothesis to be tested is: H₀: p₁ = .10,p₂ = .25,p₃ = .30,p₄ = .20,p₅ = .15. -{Student Absenteeism Narrative} Review the previous results.What is the effect of decreasing the sample size?

In 2011,Brand A MP3 Players had 45% of the market,Brand B had 35%,and Brand C had 20%.This year the makers of brand C launched a heavy advertising campaign.A random sample of electronic stores shows that of 10,000 MP3 Players sold,4,350 were Brand A,3,450 were Brand B,and 2,200 were Brand C.Has the market changed? Test at $\alpha$ = .01.

The number of degrees of freedom in testing for normality is the:

To describe a population with more than two categories you can only use a chi-squared goodness-of-fit test.

A chi-squared distribution has a shape that is ____________________.

A left-tailed area in the chi-squared distribution equals .10.For 5 degrees of freedom the table value equals 9.23635.

The sampling distribution of the test statistic for a goodness-of-fit test with k categories is a:

A large chi-squared test statistic in a test of a contingency table means you conclude:

When we describe a population of nominal data,with exactly two categories,the multinomial experiment is actually a binomial experiment with one of the categorical outcomes labeled "success" and the other labeled "failure".

Before a chi-squared test of a contingency table can be carried out,the expected values of all cells should be greater than or equal to ____________________.

The null hypothesis states that the sample data came from a normally distributed population.The researcher calculates the sample mean and the sample standard deviation from the data.The data arrangement consisted of five categories.Using $\alpha$ = .05,the appropriate critical value for this chi-squared test for normality is 5.99147.

A major insurance firm interviewed a random sample of 1,200 college students to find out the type of life insurance preferred,if any.The results follow: Insurance Preference Gender Term Whole Life Na Insurance Female 100 80 325 Male 160 60 475 Is there evidence that life insurance preference of male students is different than that of female students? Test using the 5% level of significance.

The number of degrees of freedom for a contingency table with 4 rows and 8 columns is

How do you find the probabilities needed to obtain expected frequencies for a test of a contingency table?