Catherine is at the Supermarket, and knows that she is 50 yards from her school. The map on her phone shows that the school is \large \frac{3}{4} inch from her current location.

If Catherine's current location is 3 inches from home on the same map, how far is Catherine from her home?

a
112.5 yards

b
200 yards

c
250.5 yards

d
150 yards

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.