# Confidence interval.

• Jul 6th 2011, 08:23 AM
JWEI
Confidence interval.
The owner of a petrol station wished to determine the proportion of customers who use a credit card to pay at the pump. He surveyed 200 customers and found that 120 customers use credit card to pay at the pump.Construct a 96% confidence interval for the population proportions who use a credit card to pay at the pump.

Anyone can help me solve this question?(Worried)
• Jul 6th 2011, 02:50 PM
mr fantastic
Re: Confidence interval.
Quote:

Originally Posted by JWEI
The owner of a petrol station wished to determine the proportion of customers who use a credit card to pay at the pump. He surveyed 200 customers and found that 120 customers use credit card to pay at the pump.Construct a 96% confidence interval for the population proportions who use a credit card to pay at the pump.

Anyone can help me solve this question?(Worried)

Surely your notes and/or textbook have examples to follow? What have you tried? Where are you stuck? Please be more specific in what you cannot do.