Question

A random sample of 500 army recruits has a mean height of 68 inches with a standard deviation of 2.5 inches. if a 95% confidence interval is constructed, with all conditions having been met, what is the margin of error?
A) 68
B) 6.02
C) .22
D) .184

Answer 1

Answer:

c) 0.22

Step-by-step explanation:

Explanation:-

A random sample of 500 army recruits has a mean height of 68 inches with a standard deviation of 2.5 inches.

The sample size 'n' = 500

Given the mean of the sample = 68 inches

Given standard deviation = 2.5 inches

 $Margin error = \frac{Z_{\alpha } S.D}{\sqrt{n} }$

The 95% of confidence interval ∝ = 1.96

$M.E = \frac{1.96 X 2.5}{\sqrt{500} }$

Margin of error = 0.2191 ≅0.22

Conclusion:-

The Margin of error at 95% of confidence intervals = 0.22