Question

A powder diet is tested on 49 people, and a liquid diet is tested on 36 different people. Of interest is whether the liquid diet yields a higher mean weight loss than the powder diet. The powder diet group had a mean weight loss of 42 pounds with a standard deviation of 12 pounds. The liquid diet group had a mean weight loss of 45 pounds with a standard deviation of 14 pounds.

Use the two-sample t-methods to construct a 95% confidence interval for difference in population means (μliquid− μpowder). Round your final answer to 1 decimal place. A 95% confidence is ( _____pounds, _____pounds)

Answer 1

Confidence interval :-

DF = 68

t(α/2, DF) = t(0.05 /2, 68 ) = 1.995 ( Critical value from t table )

Lower Limit =
Lower Limit = -8.8
Upper Limit =
Upper Limit = 2.8
95% Confidence interval is ( -8.8 , 2.8 )