Donating Blood to Grandma?

There is some evidence that "young blood" might improve the health, both physically and cognitively, of elderly people (or mice). In one study, old mice were randomly assigned to receive transfusions of blood from either young mice or old mice. Researchers then measured the number of minutes each of the old mice was able to run on a treadmill. The data are stored inYoungBlood. We wish to estimate the difference in the mean length of time on the treadmill, between those mice getting old blood (old

) and those mice getting young blood (young

). UseStatKeyor other technology to find a90%

confidence interval for the difference in means.

Clickherefor the dataset associated with this question.

Clickhereto accessStatKey.

Round your answers to one decimal place.

The interval forold-young

is