Given normal random variable Z , with mean μ=22.8 and standard deviation σ=6.4 , we obtain a sample of Z of size 70 . Consider the new random variable Xˉ which is the average of our sample.

1) find the interval [μXˉ−a,μXˉ+a] symmetric about μXˉ satisfying P(Xˉ∈[μXˉ−a,μXˉ+a])=0.9 is given by

Question

Given normal random variable   Z , with mean   μ=22.8   and standard deviation   σ=6.4 , we obtain a sample of   Z   of size   70 .   Consider the new random variable   Xˉ   which is the average of our sample. 

1) find the interval   [μXˉ−a,μXˉ+a]   symmetric about   μXˉ   satisfying   P(Xˉ∈[μXˉ−a,μXˉ+a])=0.9   is given by

anonymous · Answer

those x are support to be $$\bar x$$$$\mu_{\bar x }$$

tkhunny · Answer

What Z-values puts (1-0.9)/2 = 0.10/2 = 0.05 in each of the symmetric tails?

anonymous · Answer

what do  you mean ?

anonymous · Answer

you mean creating a graph ?|dw:1448740286950:dw|