A laboratory tested twelve chicken eggs and found that the mean amount of cholesterol was 199 milligrams with s = 16.5 milligrams. Construct a 95% confidence interval for the true mean cholesterol content of all such eggs.

The 95% C. I will be given as follows:

mean=199

standard deviation=16.5

n=12

thus:

value of z corresponding to 95% is 1.96, thus the 95% C. I will be found as follows:

μ+/-z (σ/√n)

thus plugging in the values we get:

199+/-1.96 (16.5/√12)

=199+/-9.3358

Answer: 199-9.3358≤x≤199+9.3358