Question

The owner of a bookstore predicts that 20% of the books she sells each week are history books. To test this prediction, the owner randomly selects 150 books out of the total number of books sold for a week and records the type of each book. The table shows the results of samples taken for 2 separate weeks. 
Choice box 1 Correct or Not correct
Choice box 2 10% 20% 30% 60%

Answer 1

To calculate the percentage of books sold we use the formula:
percentage=(Individual books sold)/(total number of books sold)
individual number of history books sold was 29 
total number of books sold=150
thus
Percentage of history books sold was:
29/150
=0.193333
~0.2
~20%
Thus we conclude that the owners prediction was  Correct . Based on prediction, about 20% of the books sold each week were history books