A school bus driver records the time (in minutes) it takes to commute to school for six days. Those results are: 25, 22, 17, 20, 15, and 10. Assuming the population is normally distributed, develop a 90% confidence interval for the population mean. What is the value of the sample standard deviation? Select one: a. 4.25 b. 3.64 O c. 5.34 d. 4.88