Question

The mean percentage of a population of people eating out at least once a week is 57% with a standard deviation of 3.50%. Assume that a sample size of 40 people was surveyed from the population a significant number of times. In which interval will 68% of the sample means occur?

Answer 1

Since 68% of the sample ranges from the plus minus first standard deviation from the mean, then interval wherein it will occur will be between 53.5% to 60.5%. I got this answer through adding and subtracting one standard deviation (3.5) from the mean (which is 57).