Confusing statistics question I am stuck on...any ideas?

How many Kleenex should the Kimberly Clark Corporation package of tissues contain? Researchers determined that 60 tissues is the average number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: = 52, s = 22. Using the sample information provided, calculate the value of the test statistic.





a) t = (52 - 60) / ( 22/100^2)


b) t = (52 - 60) / 22


c) t = (52 - 60) / ( 22/10)


d) t = (52 - 60) / ( 22/100)

Confusing statistics question I am stuck on...any ideas?
The answer is c.





The formula for the t-distribution is





sample mean (52) minus the given average (60)





divided by





the sample standard deviation (22) divided by the square root of the sample size (√100 = 10)





so you get





(52 - 60)/(22/10)
Reply:I would use the z-table as there are over 30 data points





z= (x-mean)/[sd/sqrt(n)]


(52-60)/(22/10)


z= 3.636363636