Question

The degenerative disease osteoarthritis most frequently affects weight-bearing joints such as the knee. An article presented the following summary data on stance duration (ms) for samples of both older and younger adults.

Age		Sample Size		Sample Mean		Sample SD
Older		29		805		118
Younger		15		790		75

Assume that both stance duration distributions are normal.

(a) Calculate a 99% CI for true average stance duration among elderly individuals.

(b) Carry out a test of hypotheses at significance level 0.05 to decide whether true average stance duration is larger among elderly individuals than among younger individuals. (Use μ₁ for elderly individuals and μ₂ for younger individuals.)
State the relevant hypotheses.

Calculate the test statistic and determine the P-value. (Round your test statistic to two decimal places and your P-value to three decimal places.)

State the conclusion in the problem context.

Answer 1