SOLUTION: The average grade of a subject is 1.89 for the whole class, with a standard deviation of 0.63. If a sample is 25 students is being taken, then find the probability of getting the a

Algebra ->  Statistics  -> Describing-distributions-with-numbers -> SOLUTION: The average grade of a subject is 1.89 for the whole class, with a standard deviation of 0.63. If a sample is 25 students is being taken, then find the probability of getting the a      Log On


   

Question 1161980: The average grade of a subject is 1.89 for the whole class, with a standard deviation of 0.63. If a sample is 25 students is being taken, then find the probability of getting the average of this sample to be within the range of 1.6 and 2.0.
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!

On your TI-84,

press 2nd vars 2

lower:1.6             
upper:2.0
μ:1.89
σ:0.63/√(25)         <--for √( press 2nd then x² 
Paste                 <--scroll down with down arrow key to highlight Paste

press enter

normalcdf(1.6,2.0,1.89,0.63/√(25)

press enter

0.7979936308          <--answer

Edwin