Answer:
So the mean of the given data set is approximately 15.55.
Explanation:
The mean is calculated by taking the sum of the product of each class midpoint and its corresponding frequency and dividing by the total frequency.
The midpoint of each class can be calculated as the average of the lower and upper class boundaries:
Class 0-9: Midpoint = (0 + 9) / 2 = 4.5
Class 10-19: Midpoint = (10 + 19) / 2 = 14.5
Class 20-29: Midpoint = (20 + 29) / 2 = 24.5
Now we can find the sum of the product of each midpoint and its frequency:
(4.5 * 24) + (14.5 * 20) + (24.5 * 32) = 108 + 290 + 784 = 1182
Finally, we divide this sum by the total frequency (76) to find the mean:
1182 / 76 = 15.552632
So the mean of the given data set is approximately 15.55.