A survey asks Instagram users their age group and daily usage time (in minutes). The following table shows the result.

Age 20-29	Age 30-39
50	110	60	60	40	50
60	90	60	30	30	30
40	50	40	20	50	60
70	40	100	50	40	20
40	120	50	10	30	30
50	30	120	50	20	30
60	100	60	70	10	60
90	90	50	10	70	50
10	60	60	30	20	40
20	50	40	30	30	10

Use Excel to do the following:

1. For each sample, find (i) sample mean, (ii) sample variance.

Age group 20-29: sample mean = 62.33, sample variance = 797.816 ???

Age group 30-39: sample mean = 36.00, sample variance = 314.483???

1. Assume that the population variances are equal. At the ? = 0.1 level of significance, use the p-value approach to determine whether there is evidence that the population mean for the age group 20-29 is higher than that of the age group 30-39.

P-value (one-tailed = 3.0441 > ? (0.1), so there is evidence that the mean waiting time for Age group 20-29 is more than Age group 30-39.

1. Assume that the population variances are equal. At the ? = 0.1 level of significance, use the critical value approach to determine whether there is evidence that the population mean for the age group 20-29 is higher than that of the age group 30-39.

4.325 > 1.2963 therefore there is evidence that the population mean for the age group 20-29 is higher than that of the age group 30-39.