Scores on a test are normally distributed with a mean of 70 and a standard deviation of 11.5. find p81, which separates the bottom 81% from the top 19%.

The score p81 that separates the bottom 81% from the top 19% is 80.12

Step by step:

First, calculate the "z" value. Z is a normally distributed random variable with 0 mean and standard deviation 1. The score value corresponding to the desired percentile p81 can be determined from a z value as follows:

We use a z-table (check online) to find the z value for the 81-st percentile. I found and so we use that value to calculate the score for the percentile:

The score p81 that separates the bottom 81% from the top 19% is 80.12

answer: .75 km

step-by-step explanation:

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