Question

A supermarket manager is trying to decide how many checkout registers to keep open during the early-morning hours. To aid her analysis, she recorded the number of customers who came to the supermarket during the early morning hours for the past 30 days. The data collected is presented in the table below. Construct a 95% confidence interval for the mean number of early-morning customers in the supermarket.

Day	Number of early-morning customers	Day	Number of early-morning customers
1	167	16	147
2	172	17	164
3	150	18	168
4	178	19	154
5	160	20	187
6	164	21	169
7	167	22	152
8	140	23	167
9	190	24	145
10	150	25	188
11	148	26	154
12	149	27	187
13	148	28	149
14	189	29	178
15	165	30	145

Answer 1