A Firm Claims That Only 10% of Its Accounts Receivables

Short Answer

A firm claims that only 10% of its accounts receivables are over 30 days past due.The bank that supplies working capital or interim loans to the firm is suspect of the figure and accordingly takes a random sample of 100 accounts of the firm.Find the probability that the sample proportion,p,will be:
A)between 9 and 10%.
B)within 2% points of the true proportion.