Answer:
Explanation:
In the question, there is an incomplete sentence. The complete sentence is:
"Bearing diameter is known to be normally distributed with standard deviation of 0.01 inch"
We would set up the hypothesis test.
For the null hypothesis,
H0 : µ = 1.5
For the alternative hypothesis,
H1 : µ ≠ 1.5
It is a two tailed test
Since the population standard deviation is given, z score would be determined from the normal distribution table. The formula is
z = (x - µ)/(σ/√n)
Where
x = sample mean
µ = population mean
σ = population standard deviation
n = number of samples
From the information given,
µ = 1.5
x = 1.4975
σ = 0.01
n = 25
z = (1.4975 - 1.5)/(0.01/√25) = - 1.25
Since it is a 2 tailed test, we would find the p value by doubling the area to the left of the z score to include the area to right.
Area to the left from the normal distribution table is 0.11
P value = 0.11 × 2 = 0.22
Assuming a significance level of 5%
Since 0.05 < 0.22, we would accept the null hypothesis
Therefore, at 5% significance level, we can conclude that the true mean hole diameter is 1.5 inches