A study of a local high scheel tried to determine the mean number of text

messages that each student sent per day

. The study surveyed a random

sample

of SB students in the high school and

found a mean of 190 messages sent per

day with a standard deviation of 72 messages

. At the 95% confidence level,

find the margin of error for the mean,

rounding to the nearest whole number

.

(De not write)