Question

A sample of heights of 124 American men yield a sample average of 58.87 inches. What would be the margin of error for a 95.44% CI of the average height of all such men if the population deviation is 2.9 inches?

Round to the nearest hundredth

Answer 1

Solution :  

Given that,

= 58.87

= 2.9

n = 124

At 95.44% confidence level the z is ,

  = 1 - 95.44% = 1 - 0.9544 = 0.0456

/ 2 = 0.0456 / 2 = 0.0228

Z_/2 = Z_0.0228 = 2.014

Margin of error = E = Z_/2* (/n)

= 2.014* (2.9/ 124)

= 0.52

Margin of error = 0.52