In: Math
You may need to use the appropriate appendix table or technology to answer this question.
Consider the following hypothesis test.
H0: μ = 30
Ha: μ ≠ 30
The population standard deviation is 14. Use α = 0.05. How large a sample should be taken if the researcher is willing to accept a 0.10 probability of making a type II error when the actual population mean is 34?
True mean µ = 34
hypothesis mean, µo = 30
Level of Significance , α =
0.05
std dev = σ = 14
ß= 0.1
δ= µ - µo = 4
Z (α/2)= 1.9600 [excel
function: =normsinv(α/2)
Z (ß) = 1.2816 [excel
function: =normsinv(ß)
sample size needed = n = ( ( Z(ß)+Z(α/2) )*σ / δ )² =
( ( 1.2816 + 1.960
) * 14.0 / 4 ) ²
= 128.72
so, sample size =
129