The owner of the West End Kwick Fill Gas Station wishes to determine the proportion of customers

Question:

The owner of the West End Kwick Fill Gas Station wishes to determine the proportion of customers who use a credit card or debit card to pay at the pump. He surveys 100 customers and finds that 80 paid at the pump.
a. Estimate the value of the population proportion.
b. Develop a 95% confidence interval for the population proportion.
c. Interpret your findings.