MS 150 Statistics q08 Spring 2003 8.1 • Name: _______________

In the coconut grinding competition a group of n = 36 students took an average of xbar (1K) = 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:
    normalblankii (3K)

  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 .
  8. _______ Determine the right (upper) bound for the population mean .
  9. The confidence interval for the population mean is:
    P( _________ < < _________ ) = _________
Statistic or Parameter Symbol Equations Excel
Normal Statistics
Calculate a z-statistic from an x z xbartoz.gif (1022 bytes) =(x - )/(sx/SQRT(n))
Calculate a t-statistic (t-stat) t xbartot.gif (1028 bytes) =(x - )/(sx/SQRT(n))
Calculate an x from a z   xbarfromz.gif (1060 bytes) = + zc*sx/sqrt(n)
Find a probability p from a z value     =NORMSDIST(z)
Find a z value from a probability p     =NORMSINV(p)