Power+ , Inc. produces AA batteries used in remote-controlled toy cars. The mean life of these batteries follows the normal probability distribution with a mean of 35.0 hours and a standard deviation...

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Assuming the first part asks for mean
A Mean of sampling distribution
Mean of sampling means:
µx̄ = µ = 35
B Standard deviation of sampling distribution
Standard deviation of Sample mean or Standard error:
SE = σx̄ =
σ√
n
= 5.5√
25
= 1.1 = 1.1
C P (X > 36)
Normal Distribution, µ = 35, σ = 5.5, n = 25
we convert this to standard normal using z = x− µx
σx
= x− µ
σ/
√
n
z = 36− (35)
5.5/
√
25
≈ 0.909091 ≈ 0.91
P (Z > 0.91) = Area to the right of 0.91
Z
0.1814
0.91
0
P (X > 36) = P (Z > 0.91) = 1− P (Z < 0.91) = 1− 0.8186
= 0.1814
P (Z < 0.91): in a z-table having area to the left of z, locate 0.9 in the left most column.
Move across the row to the right under column 0.01 and get value 0.8186
P (X > 36) = 0.1814 = 18.14%
D P...