Question

at a store, customers are randomly selected to participate in a survey. on friday, there were 500 customers at the store. of those, 90 were selected to participate in the survey. on saturday, the store manager expects 700 customers in the store. if the probability of being selected to participate in the survey on saturday is the same as it was on friday, how many customers will be selected to participate in the survey on saturday?

Explanation:

Step1: Calculate the probability of being selected on Friday

The probability of being selected on Friday is the number of customers selected on Friday divided by the total number of customers on Friday. So the probability $P_{Friday}=\frac{90}{500}=\frac{9}{50}$.

Step2: Use the probability to find the number of selected customers on Saturday

Let the number of customers selected on Saturday be $x$. Since the probability of being selected on Saturday is the same as on Friday, and the total number of customers in the store on Saturday is assumed to be 700. We have the equation $\frac{x}{700}=\frac{9}{50}$. Cross - multiply to get $50x = 9\times700$. Then $x=\frac{9\times700}{50}=126$.

Answer:

126