Question

A sample of 49 NBA players are randomly collected. Their average height x¯=6.7x¯=6.7 feet and the sample standard deviation is s=3.5 feet. Use these data as a pilot study to determine how many NBA players we should sample such that our 94% confidence interval is within 0.5 feet (half length of confidence interval) of the population mean?

Answer 1

Solution :

Given that,

Population standard deviation = = 3.5

Margin of error = E = 0.5

At 94% confidence level the z is ,

= 1 - 94% = 1 - 0.94 = 0.06

/ 2 = 0.06 / 2 = 0.03

Z/2 = Z0.03 = 1.881

sample size = n = (Z/2* / E) 2

n = (1.881* 3.5/ 0.5)2

n = 173.37

n = 174

Sample size =