1). Banting is believed to reduce weight when done for a minimum of 10 days. A

random sample of 5 ladies were weighed before and after Banting. The data is

displayed on a table below.

Person weight before weight after

1 85 82

2 96 90

3 105 95

4 78 90

5 120 110

Construct a 95% for the difference in mean weight.

2).Suppose you want to know the internet speed of two different mobile networks.

Network X Network Y

Sample size 12 15

Sample Mean 25 19

Sample std dev 60 50

Assuming that the population is normally distributed with equal variances.Construct a 95% for the difference in mean internet speed.

c) In a random sample, 70 of 100 men and 16 of 50 women are professional footballers. Form a 90% confidence interval for the difference between the proportion of men and the proportion of women who are professional footballers.