Can someone please help me solve this equation, I'm a little confused and not quite sure where to start, thanks!

A fitness studio want to estimate the average number of hours of exercise their clients have per week of a population of 500 members. The studio wants to start a new summer program and they need to collect data to understand their members activity levels. They took a sample of 50 members that were chosen randomly to collect data. The data has found that there's an average of 8 hours of exercise per week per member with a corrected standard deviation of 1 hour.

1- Determine the estimator of the standard deviation of the estimator of the average number of hours of exercise per member

2- Determine the upper bound of the 95% confidence interval for the average number of hours of exercise per member in the population