Exam 15: Chi-Squared Tests

Consumer panel preferences for three proposed Cafes are as follows: Use 0.05 level of significance and test to see if there is a preference among the three Cafes, according to the data.

A calculus professor posted the following grade distribution guidelines for her elementary calculus class: 8% A, 35% B, 40% C, 12% D, and 5% F.A sample of 100 elementary statistics grades at the end of last semester showed 12 As, 30 Bs, 35 Cs, 15 Ds, and 8 Fs.Test at the 5% significance level to determine whether the actual grades deviate significantly from the posted grade distribution guidelines.

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

In testing the difference between two proportions using the normal distribution, we may use either a one-tailed or two-tailed test.

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

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} Test the hypothesis at the 5% level of significance with the following frequencies: (n = 100)

The values of a chi-squared distribution are always ____________________ zero.

If you want to describe a population with two categories, you can use a(n) ____________________ test of p or the chi-squared goodness-of-fit test.

All of the expected frequencies in a chi-squared goodness-of-fit test must be equal to each other.

In the test of a contingency table, the expected cell frequencies must satisfy the rule of 5.

When the problem objective is to describe a population of nominal data with exactly two categories, we can employ either the z-test of a population proportion p, or the chi-squared goodness-of-fit test.

If we want to perform a one-tail test for differences between two populations of nominal data with exactly two categories, we must employ the z-test of p₁ -p₂.

A chi-squared test of a contingency table with 10 degrees of freedom results in a test statistic of 17.894.Using the chi-squared table, the most accurate statement that can be made about the p-value for this test is that .05 < p-value < .10.

A chi-squared test of a contingency table is applied to a contingency table with 3 rows and 4 columns for two qualitative variables.The degrees of freedom for this test must be 12.

Which of the following is not a characteristic of a multinomial 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 statistical technique is appropriate when we wish to analyze the relationship between two qualitative variables with two or more categories?

In 2011, computers of Brand A controlled 25% of the market, Brand B 20%, Brand C 10%, and brand D 45%.In 2015, sample data was collected from many randomly selected stores throughout the country.Of the 1,200 computers sold, 280 were Brand A, 270 were Brand B, 90 were Brand C, and 560 were Brand D.Has the market changed since 2011? Test at the 1% significance level.

A left tail area in the chi-squared distribution equals .99.For df = 8, the table value equals:

The Chairman of a committee has recently circulated pamphlets among the members, attempting to convince them that pension benefits should be the primary issue.A subsequent survey revealed the following breakdown of the members according to the plant at which they worked and the issue that they felt should be supported as the primary one. Do the data indicate at the 5% significant level that there are differences between the two plants regarding which issue should be the primary one?