1. In a particular population, it was of interest whether male executives are, on average, taller or shorter than their female counterparts. A random sample of 15 firms was taken with the average executive heights given in the table below.

Firm No	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
Male Height	2.07	1.81	1.81	1.78	1.89	1.62	1.82	1.67	2.07	1.82	1.84	1.75	1.79	2.06	2.04
Female Height	1.81	1.75	1.58	1.70	1.94	1.75	1.53	1.76	1.92	1.60	1.77	1.72	1.84	1.68	1.83

REQUIRED:

1. Use the above data to calculate the mean and standard deviation of the differences between the heights of the male executives and their female counterparts.
2. Discuss whether there is evidence that the mean difference in heights between male and female is non-zero.
3. Obtain a 95% confidence interval for the mean difference in heights of the male and their female colleagues.
4. A news outlet says that the average height for a male executive is above 1.77m. From the data you have, discuss whether there is enough evidence to support this claim with a 99% confidence.
5. Compare the uses of the independent samples and paired samples t tests. Explain clearly in which circumstances each method should be used in preference to the other, illustrating your answer with appropriate examples. State briefly the appropriate assumptions made in each case.
6. Look at the following daily sales data:

Day No	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
Sales	41	98	45	50	52	65	51	61	61	63	84	81	84	96	97

REQUIRED:

1. Plot a scatter graph of the dat
2. Explain whether the data appears to have any trend to it.
3. Explain whether any of the days appear to hold outliers.