Question

In a psychology journal, researchers reported that a chief executive officer's facial structure can be used to predict a firm's financial performance. The study involved measuring the facial width-to-height ratio (WHR) for each in a sample of 40 CEOs at publicly traded Fortune 500 firms. These WHR values determined by computer anah zing a photo of the CEO's face had a mean of x= 1.96 and a standard deviation of s= 0.17.

Find and interpret a 90% confidence interval for ?, the mean facial WHR for all CEOs at publicly traded Fortune 500 firms (Round to three decimal places as needed.)

Answer 1

(1.9073, 2,0127)

Step-by-step explanation:

Given;

n = 40

mean(x overbar) = 1.96

s = 0.17

(
`mean` ± Z × s )

√n

(1.96 ± 1.96 × 0.17 )

√40

(1.96 ± 0.05268)

(1.9073, 2,0127)

Interpretation: we are 90%confident that the true population mean will lie in the above confidence interval

That is, the mean facial WHR for all CEOs at publicly traded Fortune 500 firms will lie in the confidence interval (1.9073, 2,0127)