Question

A. Suppose your manager indicates that for a normally distributed data set you are analyzing, your company wants data points between z=−1.5z=-1.5 and z=1.5z=1.5 standard deviations of the mean (or within 1.5 standard deviations of the mean). What percent of the data points will fall in that range?

Answer:___ percent (Enter a number between 0 and 100, not 0 and 1 and round to 2 decimal places)

B.  Assume that z-scores are normally distributed with a mean of 0 and a standard deviation of 1.

If P(−1.2<z<b)=0.5348P(-1.2<z<b)=0.5348, find b.

b=___

C. Assume that the readings at freezing on a batch of thermometers are normally distributed with a mean of 0°C and a standard deviation of 1.00°C. A single thermometer is randomly selected and tested. Find P₉₅, the 95-percentile. This is the temperature reading separating the bottom 95% from the top 5% (round to three deimcal places).

P₉₅ = ___°C

Answer 1

A) percent of the data points will fall in that range =86.64%

B)

P(-1.2<z<b)=0.5348

P(Z<b)=0.5348+0.1151=0.6499

b=0.385

c)

P₉₅ =1.645 ^oC