To find the mean time each group spent shopping:
Group a: (14 + 20 + 46 + 34 + 58 + 31 + 41) / 7 = 244 / 7 = 34.9 minutes
Group b: (15 + 21 + 32 + 42 + 29 + 57 + 39) / 7 = 235 / 7 = 33.6 minutes
The mean time group a spent shopping is 34.9 minutes.
The mean time group b spent shopping is 33.6 minutes.
To find the difference in the mean times:
34.9 - 33.6 = 1.3
Therefore, the mean times group a and group b spent shopping differs by 1.3 minutes.