Calculate the probability of a pizza from the sample to be a cheese pizza. Notice that there is a total of 27 pizzas in the sample, and 6 of them are cheese pizzas. Therefore, the probability of a pizza being a cheese pizza, is:
[tex]\frac{6}{27}[/tex]
Multiply the probability times the total amount of pizzas that were sold to find the expected number of cheese pizzas that were sold:
[tex]\frac{6}{27}\times189=42[/tex]
Therefore, 42 pizzas are expected to be cheese.
