Engineers must consider the breadths of male heads when designing helmets. The company researchers have determined that the population of potential clientele have head breadths that are normally distributed with the mean of 6.6-in and standard deviation of 0.9-in. Due to financial constraints, the helmets will be designed to fit all men except those with head breadths that are in the smallest 2.6% or largest 2.6%. What’s the minimum head breadths and maximum head breadths?

Assume that z-scores are normally distributed with a mean of 0 and a standard deviation of 1. If , how do you find d?

the scores on an exam are normally distributed, with a mean of 85 and a standard deviation of 5. what percent of the scores are from 85 to 95? 

1. Assume the readings on thermometers are normally distributed with a mean of 0°C and a standard deviation of 1.00°C. Find the probability that a randomly selected thermometer reads greater than −1.59 and draw a sketch of the region.

2. Assume the readings on thermometers are normally distributed with a mean of 0°C and a standard deviation of 1.00°C. Find the probability P(−0.45<z<0.45)​, where z is the reading in degrees.

P(−0.45<z<0.45)=____________