A normal population has a mean of 64 and a standard deviation of 13. You select a random sample of 9.?
Compute the probability that the sample mean is: (Round your z values to 2 decimal places and final answers to 4 decimal places):
(a) Greater than 66.
(b) Less than 62.
(c) Between 62 and 66.
(I am able to find the z values, but I am getting lost when it comes to the rest of the calculations.)
- Mike GLv 71 year ago
μ = 64 and σ = 13
n = 9 so √n = 3
x̅ = Sample mean
a) z(x̅=66) = (66-64)/(13/3)
From the z-tables
P(z>0.4615) = 0.3228
b) z(x̅=62) = (62-64)/(13/3) = -0.4615
P(z<-0.4615) = 0.3228
c) P(-0.4615<z<0.4615) = 0.3544
- STEPHENLv 71 year ago
Do your own homework. If you don't understand it talk to your teacher. Me doing it for you won't teach you anything.