Suppose a researcher is interested in understanding the variation in the price of store brand milk.A random sample of 36 grocery stores selected from a population and the mean price of store brand milk is calculated.The sample mean is $3.13 with a standard deviation of $0.23.Construct a 92% confidence interval to estimate the population mean.
A) $3.03 to $3.23
B) $3.12 to $3.14
C) $3.05 to $3.21
D) $2.90 to $3.36
E) $3.06 to $3.20

Question

Quizplus · Accepted Answer

Using the formula for a confidence interval with a known population standard deviation:
CI = x̄ ± Zα/2 * σ/√n

Plugging in the given values:
CI = 3.13 ± 1.75*0.23/√36
CI = 3.13 ± 0.092
CI = (3.038, 3.222)

The closest option to this range is E: $3.06 to $3.20. Therefore, E is the best choice.

Suppose a Researcher Is Interested in Understanding the Variation in the Price