Question

The restaurant owner wants to find out what the peak demand periods are, during the hours of operation, in order to be better prepared to serve his customers.

He thinks that, on average, 60% of the daily customers come between 6:00pm and 8:59pm (equally distributed in that time) and the remaining 40% of customers come at other times during the operating hours (again equally distributed).

He wants to verify if that is true or not, so he asked his staff to write down during one week the number of customers that come into the restaurant at a given hour each day. His staff gave him the following data:

Time	Day 1	Day 2	Day 3	Day 4	Day 5	Day 6	Day 7
5:00pm-5:59pm	15	19	21	20	12	15	15
6:00pm-6:59pm	30	23	24	25	28	29	26
7:00pm-7:59pm	36	29	39	35	39	30	32
8:00pm-8:59pm	29	33	23	29	24	32	27
9:00pm-9:59pm	21	20	12	19	18	14	20
10:00pm-10:59pm	12	12	15	12	10	15	14
11:00pm-11:59pm	8	7	9	10	12	12	9

Help the manager figure out if his instincts are correct or not. Use a Chi-Squared test to see if the observed distribution is similar to the expected. Use the average demand for a given time as your observed value.

What is the p-value of your Chi-Square test?

Answer 1

Test Statistics

The number of degrees of freedom is df = 7 - 1 = 6

P-value corresponding to df = 6 and Chi-Squared statistic = 4 is 0.6767 (Obtained using online calculator. Screenshot attached)