SOLUTION: If the mean height of sorghum varieties to be 68.22 inches with a variance of 10.8 inches,how many varieties in a field of 100 varieties, would you expect to have 6 feet tall?

Algebra ->  Probability-and-statistics -> SOLUTION: If the mean height of sorghum varieties to be 68.22 inches with a variance of 10.8 inches,how many varieties in a field of 100 varieties, would you expect to have 6 feet tall?      Log On


   

Question 1071663: If the mean height of sorghum varieties to be 68.22 inches with a variance of 10.8 inches,how many varieties in a field of 100 varieties, would you expect to have 6 feet tall?
Answer by srinivas.g(540) About Me  (Show Source):
You can put this solution on YOUR website!
mean = 68.22 inches , variance = 10.8 inches
Standard deviation =sqrt%28variance%29
=+sqrt%2810.8%29
=3.2863
1 feet =12 inches
6 feet = 12*6 = 72 inches
Z score for 72 inches = +%28x-mean%29%2Fstandard+deviation

=+%2872-68.22%29%2F3.2863+
= 1.15029
From probability -z score chart, cumulative area for z = 1.15029 is 0.87493 = 87.493 %
but , we need area for z > 1.15029 ( since we need no of people 6 feet or taller)
probability = 100- 87.493 = 12.507 %
Hence probability = 12.507 %
for 100 varieties, 12.507 varieties would be 6 feet tall