Question

Wahab sells cars

The table shows information about the number of cars he sold each week for the
last 26 weeks


number of cars. Frequency
sold each week
1-5. 2
6-10. 12
11-15. 9
16-20. 3


Wahab estimates he sold a mean average of 10 cars per week
is this estimate of the mean correct

Answer 1

Wahab is correct

Explanation:

1. To find the mean of a frequency table we first need to take the middle value of the number of cars and multiply it with the weeks

2.5 x 2 = 5

8 x 12 = 96

13.5 x 9 = 121.5

18 x 3 = 54

2. Now add them all together to get

5+96+121.5+54 = 325.5

3. Since we know that the amount of weeks were 26 we can divide 325.5 by 26 however it is stated that Wahab estimates these values therefore we need to round each value to 1 significant figure which would look something like 325.5 = 300 and 26 = 30

4. Therefore 300/30 = 10 cars per week so Wahab is correct