Question

Researchers compared two groups of competitive rowers: a group of skilled rowers and a group of novices. The researchers measured the angular velocity of each subject's right knee, which describes the rate at which the knee joint opens as the legs push the body back on the sliding seat. The sample size n, the sample means, and the sample standard deviations for the two groups are given below:

Group n Mean Variance
Skilled 16 4.2 0.6
Novice 16 3.2 0.8
The researchers wished to test the hypotheses
H0: The mean knee velocities for skilled and novice rowers are the same.
Ha: The mean knee velocity for skilled rowers is larger than that for novice rowers.
The data showed no strong outliers or strong skewness so the researchers decided to use the two-sample t test. What is the value of the two-sample t statistic?

Answer 1

3.381

Explanation:

SD²=variance

t-statistic= (mean 1 -mean 2)/ √(SD1²/N1 + SD2²/N2)

= (4.2-3.2)/√(0.6/16 + 0.8/16)

= 3.381