John wants to compare two means. His sample statistics were and . Assuming equal variances, the pooled variance is:
Select one:
a. 4.5
b. 4.9
c. 5.1
d. 3.8
John wants to compare two means. His sample statistics were and . Assuming equal variances, the test statistic is:
Select one:
a. 2.37
b. 2.20
c. 1.96
d. Must know α to answer.
John wants to compare two means. His sample statistics were and . Assuming equal variances, the degrees of freedom for his test will be:
Select one:
a. 16.
b. 18.
c. 9.
d. 8.
A medical researcher wondered if there is a significant difference between the mean birth weight of boy and girl babies. Random samples of 5 babies' weights (pounds) for each gender showed the following:
Select one:
a. paired (dependent) samples t-test.
b. independent samples t-test.
c. large-sample z-test.
d. t-test for correlation.
In a test of a new surgical procedure, the five most respected surgeons in FlatBroke Township were invited to Carver Hospital. Each surgeon was assigned two patients of the same age, gender, and overall health. One patient was operated upon in the old way, and the other in the new way. Both procedures are considered equally safe. The surgery times are shown below:
a. Paired t-test
b. Independent samples t-test
c. Independent samples z test
d. Cannot be sure without knowing α
