The scatter plot shows the number of minutes guya practiced the flute each day in a given week.

what is guya's mean practice time per day during the given week? round to the nearest tenth, if necessary.

35 min
35.6 min
35.7 min
40 min

you for your ! picture is attached below.

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.