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

c) 0.22

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 = (Z_(\alpha ) S.D)/(√(n) )`

The 95% of confidence interval ∝ = 1.96

`M.E = (1.96 X 2.5)/(√(500) )`

Margin of error = 0.2191 ≅0.22

Conclusion:-

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