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29 votes
Suppose that the distance of fly balls hit to the outfield (in baseball) is normally distributed with a mean of 267 feet and a standard deviation of 39 feet. Let X be the distance in feet for a fly ball.c. Find the 70th percentile for the distribution of distance of fly balls. Round to 2 decimal places.

User Jayabalan Bala
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1 Answer

20 votes
20 votes

To find the 70th percentile we look for the z value that gives the following probability:


P(Z\leq z)=0.70

Looking at the standard normal distribution table we notice that this probability happens when:


z=0.5244

Then we need the z score to be 0.5244 .Now that we know this we use its definition to find the value of x that gives this z score:


\begin{gathered} z=(x-\mu)/(\sigma) \\ (x-267)/(39)=0.5244 \\ x-267=20.4516 \\ x=267+20.4516 \\ x=287.45 \end{gathered}

Therefore, the 70th percentile is 287.45

User Cracker
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