Question

Twenty laboratory mice were randomly divided into two groups of 10. Each group was fed according to a prescribed diet. At the end of 3 weeks, the weight gained by each animal was recorded. Do the data in the following table justify the conclusion that the mean weight gained on diet B was greater than the mean weight gained on diet A, at the α = 0.05 level of significance? Assume normality. (Use Diet B - Diet A.)

Diet A	9	11	12	13	7	10	10	6	8	5
Diet B	20	7	7	23	17	22	10	14	7	7

(a) Find t. (Give your answer correct to two decimal places.)


(ii) Find the p-value. (Give your answer correct to four decimal places.)

(b) State the appropriate conclusion.

Reject the null hypothesis, there is significant evidence that diet B had a greater weight gain.

Reject the null hypothesis, there is not significant evidence that diet B had a greater weight gain.    

Fail to reject the null hypothesis, there is significant evidence that diet B had a greater weight gain.

Fail to reject the null hypothesis, there is not significant evidence that diet B had a greater weight gain.

Answer 1

a)

test statistic t =2.07

b)

p[ value =0.0342 ( please try 0.0344 if this comes wrong)

c)

Reject the null hypothesis, there is significant evidence that diet B had a greater weight gain.