can you help me with this question

A random sample of 25 New Yorkers were asked how much sleep they got nightly. A statistical summary of the responses is given below. Researchers may be interested to use this sample data to construct a 95% confidence interval for the population mean number of hours New Yorkers sleep each night.

x=7.73, s=0.77, n=25

Use this sample data to determine whatsize sampleis needed to estimate the true average hours of sleep for New Yorkers within 0.15 hours.