Chapter 11 Assignment
two-Sample Tests of Hypothesis
Part I Select the correct answer and write the appropriate letter in the space provided.
______ 1. The test statistic for testing a hypothesis for large sample means when the population standard deviation is not known is
a. the t distribution. b. the F distribution.
c. the z distribution. d. the m distribution.
______ 2. We want to test a hypothesis for the difference between two population means. The null and alternate hypothesis are indicated:
a. A left-tailed test should be applied
b. A right-tailed test should be applied
c. A two-tailed test should be applied
d. We cannot determine whether a left, right or two-tailed test to apply without more information
______ 3. In a large sample test of means, both samples must have at least:
a. 120 items b. 90 items
c. 60 items d. 30 items.
______ 4. In a two-sample test of means for independent samples, n1 = 12 and n2 = 10. How many degrees of freedom are in the test?
a. 22 b. 21
c. 20 d. none of the above
______5. In the paired t-test, we assume in the null hypothesis that the distribution of the differences between the paired observation has a mean
a. equal to 1. b. equal to n - 1.
c. equal to 0. d. none of the above
______ 6. For a particular significance level and sample size the value of the t for a one-tailed test is
a. always less than z. b. always more than z.
c. equal to 0. d. equal to z.
______ 7. Which of the following is not an assumption for the two-sample t-test?
a. equal sample variances b. independent samples
c. normal populations d. equal population standard deviations
______ 8. For dependent samples, we assume the distribution of the differences in the populations has a mean of:
a. 30 b. 0
c. 25 d. none of the above
______ 9. For tests of hypothesis for a two-sample means, sample size greater than 30, a one-tailed test (rejection region in the upper tail), using the 0.01 significance level, the critical value is:
a. 2.18 b. 2.68
c. 2.33 d. 3.12
______ 10. To determine if a diet supplement is useful for increasing weight, patients are weighed at the start of the program and at the end of the program. This is an example of a(n)
a. test of paired differences. b. independent sample.
c. one-sample test for means. d. two-sample test for means.
Chapter 12 Assignment
Analysis of Variance
______ 1. The analysis of variance technique is a method for
a. comparing three or more means. b. comparing F distributions.
c. measuring sampling error. d. none of the above.
______ 2. A treatment is
a. a normal population. b. the explained population.
c. a source of variation. d. the amount of random error.
______ 3. In a one-way ANOVA, k refers to the
a. number of observations in each column. b. the number of treatments.
c. the total number of observations. d. none of the above.
______4. The F distribution is
a. a continuous distribution. b. based on two sets of degrees of freedom.
c. never negative. d. all of the above
______5. In an ANOVA test there are 5 observations in each of three treatments. The degrees of freedom in the numerator and denominator respectively are:
a. 2, 4 b. 3, 15 c. 3, 12 d. 2, 12
______ 6. Which of the following assumptions is not a requirement for ANOVA?
a. dependent samples b. normal populations
c. equal population variances d. independent samples
______ 7. The mean square error term (MSE) is the
a. estimate of the common population variance. b. estimate of the population means.
c. estimate of the sample standard deviation. d. treatment variation.
_______8. In a one-way ANOVA, the null hypothesis indicates that the treatment means
a. are all the same or from equal populations. b. are not from the same populations.
c. in at least one pair of means are the same. d. are all different.
______9. The appropriate test statistic for comparing two sample variances to find out if they came from the same or equal populations is the
a. t distribution. b. z distribution.
c. F distribution. d. binomial distribution.
_____ 10. What is the probability for an F of more than 6.55 with 3 degrees of freedom in the numerator and 10 in the denominator?
a. 0.025 b. 0.001
c. 0.01 d. 0.05