Answer :
There is enough evidence to conclude that the doctor's claim is true.
We have given that,
population mean μ = 11 pounds
sample size n = 25
sample mean x = 12 ponds
standard deviation σ = 4 pounds
so the null hypothesis is H₀ : μ = 11 pounds
and the alternative hypothesis is Hₐ : μ > 11 pounds
now we will calculate test statistics,
t = (x-μ)/(σ/√n)
= (12 - 11)/(4/√25)
= 1/(4/5)
t = 1.25
p-value from the z-table is 0.10565
the result is non significant at p < 0.01.
Hence the null hypothesis rejected .
Therefore there is enough evidence to conclude that the doctor's claim is true.
The level of significance is the measurement of the statistical significance. It defines whether the null hypothesis is assumed to be accepted or rejected. It is expected to identify if the result is statistically significant for the null hypothesis to be false or rejected.
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