A market researcher gathered information on a random sample of 49 customers in order to calculate the average amount of money spent by all restaurant patrons. Assume that the $2.50 standard deviation of the total amount spent by diners at the restaurant. Create the related 95% confidence interval if the sample's mean customer spending is $22.60. Interpretation: We are attempting to determine the percentage of university students overall who use at least one major credit card. 140 out of 200 students who were chosen at random for the study use at least one major credit card. Calculate a 95% confidence interval for the percentage of university students overall who use at least one major credit card. Interpretation: