### MS 150 Statistics q08 Spring 2003 8.1 • Name: _______________

In the coconut grinding competition a group of n = 36 students took an average of = 3 minutes with a sample standard deviation sx = 1 minute.

1. Use the information above to sketch the 95% confidence interval and other information to set up this problem:

2. _______ Determine the area in the left tail.
3. _______ Determine the area in the right tail.
4. _______ Determine the area to the left of the right tail.
5. _______ Determine the left z value.
6. _______ Determine the right z value.
7. _______ Determine the left (lower) bound for the population mean µ.
8. _______ Determine the right (upper) bound for the population mean µ.
9. The confidence interval for the population mean µ is:
P( _________ < µ < _________ ) = _________
Statistic or Parameter Symbol Equations Excel
Normal Statistics
Calculate a z-statistic from an x z =(x - µ)/(sx/SQRT(n))
Calculate a t-statistic (t-stat) t =(x - µ)/(sx/SQRT(n))
Calculate an x from a z   =µ + zc*sx/sqrt(n)
Find a probability p from a z value     =NORMSDIST(z)
Find a z value from a probability p     =NORMSINV(p)