A random sample n= 15 is taken from a population assumed to be normal,and = 1.2 and s = .6.Calculate a 98 percent confidence interval for μ.
A) [.675,1.725]
B) [.794,1.606]
C) [.876,1.524]
D) [.882,1.518]

Question

Quizplus · Accepted Answer

To calculate a 98% confidence interval for μ, we use the formula:

CI = X̄ ± zα/2 * (s/√n)

where:
X̄ = sample mean = 1.2
zα/2 = critical value for a 98% confidence interval = 2.33 (from a z-table or calculator)
s = sample standard deviation = 0.6
n = sample size = 15

Plugging in the values, we get:

CI = 1.2 ± 2.33 * (0.6/√15)
CI = [0.794, 1.606]

Therefore, the best choice is B, which matches our calculated interval.

A Random Sample N= 15 Is Taken from a Population