21. The table shows data from a school exercise program.
Exercise Program Information
Type
Target Rate
(kilometers Start Time
per hour)
End
Time
Walking
3.5
8:30 A. M. 10:00 A. M.
Jogging
8.5
7:15 A. M. 8:30 A. M.
Biking
19.5
11:50 A. M.] 2:05 P. M.
If Malinda jogs at the target rate, how
far will she travel?

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.