SOLUTION: A researcher studying frogs is investigating the distance that a certain species of frog can jump. The jump-lengths are normally distributed with a mean of 90 inches and a standard

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Question 1191056: A researcher studying frogs is investigating the distance that a certain species of frog can jump. The jump-lengths are normally distributed with a mean of 90 inches and a standard deviation of 12 inches.
Use the Empirical Rule to answer the following questions.
a) What percent of frog-jumps of this species are less than 78 inches?
__%
b) What jump-lengths represent the middle 95% of frog jumps of this species?
From
___inches to ___inches
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
z=(x-mean)/sd
so a is asking what percent are more than 1 sd less than the mean. This is 16%, since 32% probability is more than 1 sd from the mean in both directions, and we only want half of that.
-
The middle 95% of jumps are within + and - 2 sd s of the mean
This is 66 inches from the low end (90-2*12) and 114 inches from the top end (90+2*12)