SOLUTION: Candidates for employment at a city fire department are required to take a written aptitude test. Scores on this test are normally distributed with a mean of 260 and a standard de
Algebra ->
Probability-and-statistics
-> SOLUTION: Candidates for employment at a city fire department are required to take a written aptitude test. Scores on this test are normally distributed with a mean of 260 and a standard de
Log On
Question 904018: Candidates for employment at a city fire department are required to take a written aptitude test. Scores on this test are normally distributed with a mean of 260 and a standard deviation of 51. A random sample of nine (9) test scores is taken. What is the probability that the sample mean score is less than 250? (express as a decimal, not a percentage Answer by ewatrrr(24785) (Show Source):
You can put this solution on YOUR website! s = 51/sqrt(9) = 17
t(250) = (250-260)/17 = -.588
p-value =P(t< -.588 when df = 8) = tcdf(-100, -.588, 8)
Recommend following references:
http://stattrek.com/online-calculator/t-distribution.aspx
for use of TI Calculator (Calculator a must)
http://www.youtube.com/watch?v=S81bgxKI-cI
