According to Franchise Business Review, over 50% of all food franchises earn a profit of less than $50,000 a year. In a sample of 142 casual dining restaurants, 81 earned a profit of less than $50,000 last year.

1) What is the point estimate of the proportion of casual dining restaurants that earned a profit of less than $50,000 last year?

2) Determine the margin of error and provide a 95% confidence interval for the proportion of casual dining restaurants that earned a profit of less than $50,000 last year.

3) How large a sample is needed if the desired margin of error is .03?