A survey of 25 randomly selected "iPhone" owners showed that the purchase price has a mean of $394 with a sample standard deviation of $190. a. Compute the standard error of the sample mean. (Round the final answer to the nearest whole number.) Standard error b. Compute the 80% confidence interval for the mean. (Round the final answers to 2 decimal places.) The confidence interval is between $ and $ c. How large a sample is needed to estimate the population mean within $14 at a 80% degree of confidence? (Round the final answer to the nearest whole number.) Sample sizeThe National Bank, like most other large banks, found that using automatic teller machines (ATMsJ reduces the cost ot routine bank transactions. National installed an ATM in the corporate offices of the Fun Toy Company. The ATM is for the exclusive use of Fun's 610 employees. After several months of operation. a sample of 100 employees revealed the following use of the ATM machine by Fun employees in a month: lumber of 11m m Used Frequency 20 30 20 UbUMl-'D 20 a. What is the estimate of the proportion of employees who do not use the ATM in a month? Pro portion |:| 96 b-1. For estimate of the proportion of employees who do not use the ATM in a month, develop a 90% condence interval. {Round the nal answers to 3 decimal places.) 90% cond ence interval is a nd b-2. Can National be sure that at least 40% of the employees of Fun Toy Company will use the ATM? c. How many transactions does the average Fun employee make per month? {Round the final answer to 2 decimal places} Total transactions UI U 20 a. What is the estimate of the proportion of employees who do not use the ATM in a month? Proportion % b-1. For estimate of the proportion of employees who do not use the ATM in a month, develop a 90% confidence interval. (Round the final answers to 3 decimal places.) 90% confidence interval is and b-2. Can National be sure that at least 40% of the employees of Fun Toy Company will use the ATM? (Click to select) v c. How many transactions does the average Fun employee make per month? (Round the final answer to 2 decimal places.) Total transactions d. Develop a 90% confidence interval for the mean number of transactions per month. (Round the final answers to 3 decimal places.) 90% confidence interval for the mean number of transaction per month is and e. Is it possible that the population mean is 0? (Click to select) v