1) In a random sample of 80 staff members in company. A spent an average of 40mins commuting from home to the office, while another random sample of 41 staff members in company B spent an average of 25mins commuting from home to the office. The standard deviation for the sample of staff members in company A was 5 mins, while the standard deviation for the sample of staff members in company B was 10 mins.

1-1) Calculate and approximate 95% confidence interval for the difference in average amounts spent on food expenses per month( commuter - non commuters)

1-2) interpret your interval calculated above.

2) A randomly selected of n = 62 men in Canada had an average marriage length of 25 years. The sample standard deviation was 5 Years.

2-1) calculate a 98% confidence interval for the average marriage length of all women in American.

2-2) interpret your interval calculated above.