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Please help with statistics probability question?
The height of men in the USA are normally distributed with a mean of 68 inches and a standard of 4 inches. What is the probability that the mean height of a random sample of 35 men is greater than 70 inches?
1 Answer
- 1 decade agoFavorite Answer
the std dev of sample means (ss) is std dev of pop/sqrt(sample size)
ss= 4/sqrt(35)=4/5.92=0.68
z=(xbar-mean)/sd
change 70 to a z-score
z=(70-68)/0.68
z=2/0.68
z=2.94
central area for z=2.94 is .4984
area in question is to right of that area (tail end)
subtract from .5
.5000-.4984=.0016 (answer)
Source(s): http://www.math911.com/