Content Quiz Ch 8 (2-sample and chi-squared)

Consider a hypothesis test of difference of means for two independent populations x1 and x2. Suppose that both sample sizes are greater than 30 and that you know σ1 but not σ2. Is it standard practice to use the normal distribution or a Student's t distribution? A. Use the Student's t distribution because we do not know σ2. B. Use the normal distribution because both sample sizes are greater than 30. C. Use the Student's t distribution because both sample sizes are greater than 30. D. Use the normal distribution because we do not know σ2.

A. Use the Student's t distribution because we do not know σ2.

When testing the difference of means for paired data, what is the null hypothesis? A. Ho: μd < 0 B. Ho: μd = 0 C. Ho: μd > 0 D. Ho: μd ≠ 0

B. Ho: μd = 0

When conducting a paired differences test, what is the value of n? A. The number of data pairs minus 1. B. The number of data pairs. C. The total number of data values minus 1. D. The total number of data values.

B. The number of data pairs.

When conducting a test for the difference of means for two independent populations x1 and x2, what alternate hypothesis would indicate that the mean of the x2 population is smaller than that of the x1 population? Express the alternate hypothesis in two ways. A. H1: μ1 = μ2 or H1: μ1 - μ2 = 0 B. H1: μ1 > μ2 or H1: μ2 - μ1 > 0 C. H1: μ1 > μ2 or H1: μ1 - μ2 > 0 D. H1: μ1 < μ2 or H1: μ1 - μ2 < 0

C. H1: μ1 > μ2 or H1: μ1 - μ2 > 0

Consider a hypothesis test of difference of means for two independent populations x1 and x2. What are two ways of expressing the null hypothesis? A. H0: μ1 = μ2 or H0: μ1 + μ2 = 0 B. H0: μ1 < μ2 or H0: μ1 - μ2 < 0 C. H0: μ1 > μ2 or H0: μ1 - μ2 > 0 D. H0: μ1 = μ2 or H0: μ1 - μ2 = 0

D. H0: μ1 = μ2 or H0: μ1 - μ2 = 0

In general, are chi-square distributions symmetric or skewed? If skewed, are they skewed right or left? A. symmetric B. skewed right or left C. skewed left D. skewed right

D. skewed right

Are data that can be paired independent or dependent?

dependent

[WEBASSIGN] A Michigan study concerning preference for outdoor activities used a questionnaire with a six-point Likert-type response in which 1 designated "not important" and 6 designated "extremely important." A random sample of n1 = 50 adults were asked about fishing as an outdoor activity. The mean response was x1 = 4.9. Another random sample of n2 = 41 adults were asked about camping as an outdoor activity. For this group, the mean response was x2 = 5.7. From previous studies, it is known that σ1 = 1.3 and σ2 = 2.0. Does this indicate a difference (either way) regarding preference for camping versus preference for fishing as an outdoor activity? Use a 5% level of significance.

Z test- 2 sample

Ceremonial Ranking Cooking Jar Sherds Decorated Jar Sherds (Noncooking) Row Total A 84 51 135 B 96 49 145 C 79 75 154 Column Total 259 175 434

Chi-squared test-chi-2way [Mat >]

Consider a set of data pairs. What is the first step in processing the data for a paired differences test? What is the symbol for the sample test statistic? Describe the value of the sample test statistic. A. Take the paired differences. The test statistic symbol is x, which is the mean of the paired differences. B. Take the squared differences. The test statistic symbol is d, which is the mean of the squared differences. C. Take the paired differences. The test statistic symbol is d, which is the mean of the paired differences. D. Take the paired differences. The test statistic symbol is d, which is the sample standard deviation of the paired differences.

C. Take the paired differences. The test statistic symbol is d, which is the mean of the paired differences.

When using a Student's t distribution for a paired differences test with n data pairs, what value do you use for the degrees of freedom? A. 2n B. 2n - 1 C. n - 1 D. n

C. n - 1

[WEBASSIGN] A: 12.4 13.4 12.4 13.2 11.8 13.4 14.2 15.1 B: 13.1 9.9 14.7 12.3 10.7 13.5 10.9 10.0 A: 12.5 12.3 13.1 15.8 10.3 12.7 11.1 15.7 B: 14.1 13.6 9.1 10.2 17.9 11.8 7.0 9.2 Do the data indicate a difference (either way) between population average birth rate and death rate in this region? Use α = 0.01. (Let d = A − B.)

Calc d (A-B) Plug in both d sets in List 1 t-test...1 sample...u=0