In: Statistics and Probability
Suppose you randomly sample 64 cans and find the mean amount of Coke in this sample is 11.85 ounces and the standard deviation is 0.35 ounces. Construct a 95% confidence interval estimate for the mean amount of Coke in the all such cans.
Solution :
Given that,
= 11.85
= 0.35
n = 64
At 95% confidence level the z is ,
= 1 - 95% = 1 - 0.95 = 0.05
/ 2 = 0.05 / 2 = 0.025
Z/2 = Z0.025 = 1.96
Margin of error = E = Z/2* ( /n)
= 1.96* (0.35 / 64)
= 0.09 (rounded)
At 99% confidence interval estimate of the population mean is,
- E < < + E
11.85-0.09 < < 11.85+0.09
11.76< < 11.94