Question

Assume that the readings on the thermometers are normally distributed with a mean of 0 degrees and standard deviation of 1.00degreesC. A thermometer is randomly selected and tested. Draw a sketch and find the temperature reading corresponding to Upper P 85​, the 85 th percentile. This is the temperature reading separating the bottom 85 % from the top 15 %.

Answer 1

solution:

mean = = 0

standard deviation = = 1

Using standard normal table,

P(Z < z) = 85%

=(Z < z) = 0.85  

= P(Z < z ) = 0.85  

z = 1.04

Using z-score formula  

x = z +

x = 1.04 *1+0

x = 1.04

85 th percentile. This is the temperature reading separating the bottom 85 % from the top 15 %.

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Submit answer 1.04