Question

48) A laboratory tested twelve eggs and found that the average amount of cholesterol in each egg was 185 milligrams, with a sample standard deviation of 17.6 mg. Construct a 95% confidence interval for the mean cholesterol content in a typical egg.

Answer 1

The C.I. at 95% is 185±9.9583 or C.I.[175 to 195].

Explanation:

Given:

Mean =185 mg

Standard deviation=17.6

Total number of samples=12

To Find:

95% of Confidence interval .

Solution:

We know that formula for C.I is given by ,

C.I.=mean±Z[standard deviation/Sqrt(Total no of samples)]

So using all above given values we get ,

Here Zscore at 95% is Z=1.96

So

C.I.=185±1.96[17.6/Sqrt(12)]

=185±1.96[17.6/3.464]

=185±1.965[5.0808]

=185±9.9583

In short C.I. is given as at 95% C.I.[175 to 195].