The predicted value of hardness at 37 hours is 243.87 and an 85% confidence interval for the mean hardness is (242.12, 245.61). At 41 hours, the predicted hardness is 252 and an 85% confidence interval for mean hardness is (249.83, 254.18). The confidence interval for X is equals to 41 which is wider because the value 41 is farther away from the sample mean X than is 37. As an outcome, the standard error for the prediction is larger.
The answer is 1620.
simple
I do not understand the context of your question, you need extra information to find this out like a picture or a word problem.
If the angles equal each other you would have to solve for x when angle 7 and 8 equal each other. SO... based on that, x would equal 15. This means measure of angle 7 would equal 45 and measure of angle 8 would equal 45. This may not be true because I have no idea what you are asking
