Answer
$\bar{x}$ = 25 months μ=31 months,σ=7.2months,$σ_\bar{s}$$ \frac{7.2}{$16}$=1.8, n = 16
α = 0.025, df = 16-1=15, critical value=2.131
t=$ \frac{\bar{x}-μ }{σ_\bar{s}}$
= $ \frac{25-31 }{1.8}$
=-3.333
Rejection region = z < 2.131
Non rejection region = z >= 2.131
The value z =-3.333 falls within the rejection region, hence we reject the null hypothesis and claim that the editor’s claim is false.
The probability of making a Type I error : α =0.025
If the probability of making a Type I error is 0.001,
critical value = 3.733, since the value z =-3.333 falls within the non-rejection region, hence we failed to reject the null hypothesis and claim that the editor’s claim is true.
Work Step by Step
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