Answer: 60.93 < μ < 69.07
Step-by-step explanation: The true mean of a set of data is between an interval of values with a percentage of precision, e.g., a <u>99% confidence interval</u> means we are 99% confident the true mean is between the lower and upper limits.
To find the interval, use
x±
z is z-score related to the % of confidence level
In this case, a 99% confidence interval is 2.576
x is sample mean
Calculating:
x = 65
65±
65±4.07
Confidence Interval: 60.93 < μ < 69.07
Meaning that we are 99% sure the population means is between 60.93 and 69.07.