An article gave the accompanying data on ultimate load (kN) for two different types of beams.

Type	Sample Size	Sample Mean	Sample SD
Fiberglass grid	25	31.4	2.1
Commercial carbon grid	25	41.8	4.4

a) Assuming that the underlying distributions are normal, calculate a 99% CI for the difference between true average load for the fiberglass beams and carbon beams, _{fiberglass carbon}. (Round your answer to two decimal places.)

(b)Does the upper limit of the interval you calculated in part (a) give a 99% upper confidence bound for the difference between the two 's? If not, calculate such a bound. (Round your answer to two decimal places. If the upper limit of the interval calculated in part (a) does give the 99% upper confidence bound, enter that value.)