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Been looking for help for 2 hrs hopefully you can help.Hi I got help on part b so I only need help with part a.

Been looking for help for 2 hrs hopefully you can help.Hi I got help on part b so-example-1
User LBPLC
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1 Answer

2 votes

Given:

- The Mean:


\mu=19.9

- The Standard Deviation:


\mu=33.1

You have to find:


P(x>8.9)

You need to find the z-statistic using this formula:


z=(x-\mu)/(\sigma)

In this case:


x=8.9

Then:


z=(8.9-19.9)/(33.1)\approx-0.332

You need to find:


P(z>-0.332)

By symmetry, this is equal to:


P(z<0.0332)

Using the Normal Distribution Table, you get:


P(z<0.0332)=0.6293

Hence, the answer is:


P(x>8.9)=0.6293

User Suh
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