Assume that the heights of bookcases are normally distributed. A random sample of 16 bookcases in one company have a mean height of 67.5 inches and a standard deviation of 2.1 inches. Construct a 99% confidence interval for the population standard deviation, σ.

The Confidence Interval = (66.1476, 68.8524)

Step-by-step explanation:

The formula for confidence interval of a normal distribution is given as:

Confidence Interval = μ ± z × σ/√n

Where:

μ is the mean height = 67.5

σ is the standard deviation = 2.1 inches

n is the number of samples = 16 bookcases

z = 99% confidence interval = 2.576

Confidence Interval = 67.5 ± 2.576 ×2.1√16

= 67.5 ± 2.576 × 2.1/4

Confidence Interval = 67.5 ± 1.3524

67.5 - 1.3524 = 68.8524

67.5 + 1.3524 = 66.1476

Therefore, the Confidence Interval = (66.1476, 68.8524)

the correct answer is the second option

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