Answer to Question #166840 in Statistics and Probability for Ivy Grace

Question #166840

the time for a major exam to be completed is normally distributed with an average of 55 minutes and a standard deviation of 9 minutes. If 92% of the student completed the exam, when should the test be terminated?


1
Expert's answer
2021-02-26T04:51:41-0500

Mean(μ\mu ) = 55

Standard deviation(σ\sigma )= 9



According to question, P(z) = 0.92

Using Standard Normal Distribution Chart



z= 1.405

By normal distribution formula, z=xˉμσz=\dfrac{\bar x-\mu}{\sigma}

1.405=xˉ5591.405=\dfrac{\bar x-55}{9}

xˉ=67.645\Rightarrow \bar x = 67.645


Hence the test will be terminated after 67.6 minutes.

Need a fast expert's response?

Submit order

and get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!

Comments

No comments. Be the first!

Leave a comment