QM quizes 3-4

Which of the following is not a basic concept behind analysis of variance? Select one: a. It is used to determine if samples have been drawn from populations having the same mean. b. It allows us to drop the assumption of equal variances in the parent population if the sample sizes are large enough. c. It assumes each sample is drawn from a normally distributed population. d. It uses the comparison of two estimates of the population variance to test its hypothesis.

B.

In testing hypotheses, the researcher initially assumes that the __________. Select one: A. alternative hypothesis is true. B. null hypothesis is true C. errors cannot be made D. the population parameter of interest is known

B.

We cannot compute multiple t-tests without altering α if we have more than two groups because: Select one: a. We would violate the homogeneity of variance assumption. b. α would increase based on the number of t-tests you would perform. c. We must determine if F is significant first. d. All of the above.

B.

When df increases, i.e. df=10 the Chi-Square distribution: Select one: a. Becomes more platykurtic. b. Approaches a normal distribution. c. Becomes more leptokurtic d. None of the above, df do not affect the Chi-Square distribution.

B.

A variable contains seven categories. It is expected that data are uniformly distributed across these seven categories. To test this, a sample of observed data is gathered on this variable resulting in frequencies of 27, 30, 29, 21, 18, 33 and 24. What is the value of test statistic equals to, using a significance level of 1%? Select one: a. 18.475 b. 10.645 c. 6.46 d. 0.374

C.

The F-statistic, as used in the analysis of variance: Select one: a. Has as its numerator a value which is an unbiased estimate of the population variance. b. Has as its denominator a value which is an unbiased estimate of the population variance. c. Compares an estimate of the variance of the sample means with an estimate of the variance of the population. d. Is the ratio of between group variance to within group variance.

D.