Exam 10: The t Test for Two Independent Samples

A researcher conducts an independent-measures study examining the effectiveness of a group exercise program at an assisted living facility for elderly adults.One group of residents is selected to participate in the program,and a second group serves as a control.After 6 weeks,the researcher records a combined score measuring balance and strength for each individual.The data are as follows: Control Exercise n=10 n=15 M=12 M=15.5 SS=120.5 SS=190.0 a.Does the exercise program have a significant effect? Use an alpha level of .05, two tails. b.Compute Cohen's d to measure the size of the treatment effect.

For a hypothesis test with the independent-measures t statistic,the null hypothesis states that the two population means are the same and the homogeneity assumption states that the two population variances are the same.

Which set of sample characteristics is most likely to produce a significant value for the independent-measures t statistic and a large effect size?

If the two samples are the same size,the degrees of freedom for the independent measures t statistic will be an even number.