A Group of Statistics Students Decided to Conduct a Survey

Multiple Choice

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spend studying per week.Based on a simple random sample,they surveyed 144 students.The statistics showed that students studied an average of 20 hours per week with a standard deviation of 10 hours.What is the probability of finding a sample mean less than 18 hours?

A) 0.4820
B) 0.4920
C) 0.0080
D) 0.0180