I have everything excepr the standard deviation

Find the mean, median, mode, and standard deviation for the given population. 17) The number of vehicles passing through a bank drive-up line during each 15-minute period was recorded. The results are shown below. Find the mean, median, mode, and standard deviation of the population data below. 23 25 23 16 26 23 28 28 33 29 29 27 22 29 23 18 13 26 24 15 mean= 24 median = 24.5 mode = 23 Standard deviation =