Question

The following frequency table summarizes the ages of 50 customers for both shopping stores,

Customer ages	Frequency – Macy’s	Frequency – J.C Penny’s
15-23	8	2
24-32	19	11
33-41	8	7
42-50	6	11
51-59	3	11
60-68	6	8

50                                    50

1. Compute, the mean and standard deviation per customer age group for both shopping stores in excel
2. Distinguish the customers for each store per the results

Answer 1

Note - Midpoint is calculated by taking sum of upper & lower limit and then dividing it by 2.

For Macy's -

Formula for mean is -

Formula for calculating standard deviation -

Standard deviation =

Where,

Hence,

Standard deviation = =

For peeny's -

Formula for mean is -

Formula for calculating standard deviation -

Standard deviation =

Where,

Hence,

Standard deviation = =

From above result -

Mean age for macy's store is 36.1 years while for penny's store is 44.56 years. This also means that average age group for macy's store is 33 to 41 years & for penny's store is 42 to 51 years.

From standard deviation, we can say that customer age between 22 & 50 comes to the macy's store more than penny's store. While, customers age between 31 & 58 comes to penny's store more than macy's store.