Golf cart attendants at a local country club often receive tips from golfers they assist with golf clubs. To help recruit new employees, the country club would like to determine the average tips per day an attendant earns. A sample of 14 attendants averaged $38. 11 per day in tips. Assume the population standard deviation for daily tips is $8.69. Complete parts a and b below. a. Construct a 96% confidence interval to estimate the average daily tips for an attendant. The average daily tips for an attendant is between a lower limit of $ and an upper limit of $ 7. (Round to the nearest cent as needed.) b. What assumption needs to be made to construct this interval? O A. The population must be normally distributed. O B. The sample standard deviation must be equal to the population standard deviation. O C. The population mean must be contained in the confidence interval. O D. The sample size must be less than 30