To find the mean shopping time for each group, you can use the following formula for the mean:
\[ \text{Mean} = \frac{\text{Sum of all values}}{\text{Number of values}} \]
For Group A:
- Shopping times: 18, 20, 46, 34, 58, 31, 41
- Sum of times = 18 + 20 + 46 + 34 + 58 + 31 + 41 = 248
- Number of values = 7
\[ \text{Mean for Group A} = \frac{248}{7} \approx 35.43 \text{ minutes} \]
For Group B:
- Shopping times: 15, 21, 32, 42, 29, 57, 39
- Sum of times = 15 + 21 + 32 + 42 + 29 + 57 + 39 = 235
- Number of values = 7
\[ \text{Mean for Group B} = \frac{235}{7} \approx 33.57 \text{ minutes} \]
Determine the difference in mean times:
\[ \text{Difference} = \text{Mean of Group A} - \text{Mean of Group B} = 35.43 - 33.57 \approx 1.86 \text{ minutes} \]
Final answers:
The mean time group A spent shopping is 35.4 minutes (rounded to 1 decimal place).
The mean time group B spent shopping is 33.6 minutes (rounded to 1 decimal place).
The mean times group A and group B spent shopping differ by 1.9 minutes (rounded to 1 decimal place).