What is the optimal time for a scuba diver to be on the bottom of the ocean? That depends on the depth of the dive. The US navy has done a lot of research on this topic. The navy defines the "optimal...

What is the optimal time for a scuba diver to be on the bottom of the ocean? That depends on the depth of the dive. The US navy has done a lot of research on this topic. The navy defines the "optimal time" to be the time at each depth for the best balance between length of work period and decompression time after surfacing. Let x= depth of dive in meters and let y= optimal time in hours. A random sample of divers gave the following data.
x 16.1 25.3 29.2 38.3 51.3 20.5 22.7

y 2.68 2.28 1.68 1.03 .75 2.38 2.20

find the predicted optimal time in hours for a dive depth of x=33 meters.(round your answer to two decimal places)

__hr

find an 80% confidence interval for y when x =33 meters.(round your answer to two decimal places)

lower limit=
upper limit=

use a 1% level of significance to test the claim that b<0. (round="" two="" decimal="">

t=
critical t =

find a 90% confidence interval for b and interpret its meaning. (Round threee decimal places)

lower limit=
upper limit=