Answer:
Correct option:
We are 95% certain that the confidence interval of 18.6 to 21.3 includes the true average number of chocolate chips per cookie.
Step-by-step explanation:
The general formula for the (1 - <em>α</em>)% confidence interval for population<em> </em>mean is:
Here:
= sample mean
CV = critical value
= standard error of mean.
The (1 - <em>α</em>)% confidence interval for population parameter implies that there is a (1 - <em>α</em>) probability that the true value of the parameter is included in the interval.
Or, the (1 - <em>α</em>)% confidence interval for the parameter implies that there is (1 - <em>α</em>)% confidence or certainty that the true parameter value is contained in the interval.
The 95% confidence interval for the mean number of chocolate chips per cookie is (18.6, 21.3).
This 95% confidence interval implies that there is a 0.95 probability that the true mean number of chocolate chips per cookie is between 18.6 and 21.3.
Thus, the correct option is:
"We are 95% certain that the confidence interval of 18.6 to 21.3 includes the true average number of chocolate chips per cookie. "