19. The Toylot company makes an electric train with a motor that it claims will draw an average of only 0.8 ampere (A) under a normal load. A sample of nine motors was tested, and it was found that the mean current was x = 1.30 A, with a sample standard deviation of s = 0.41 A. Do the data indicate that the Toylot claim of 0.8 A is too low? (Use a 1% level of significance.)

What are we testing in this problem?

single proportion

single mean

(a) What is the level of significance?

.

What is the value of the sample test statistic? (Round your answer to three decimal places.)

20. A hospital reported that the normal death rate for patients with extensive burns (more than 40% of skin area) has been significantly reduced by the use of new fluid plasma compresses. Before the new treatment, the mortality rate for extensive burn patients was about 60%. Using the new compresses, the hospital found that only 43 of 91 patients with extensive burns died. Use a 1% level of significance to test the claim that the mortality rate has dropped.

What are we testing in this problem?

single mean

single proportion