Assume the readings on thermometers are normally distributed

Assume the readings on thermometers are normally distributed with a mean of 0 degrees Celsius and a standard deviation of 1.00 degrees Celsius. Find the probability that a randomly selected thermometer reads between -1.18 and -0.55 and draw a sketch of the region. The probability is

Solution

Reading of thermometer X is N(0,1)

This implies x = Z = the std normal variate

Hence prob for this can be found from standard normal distribution table.

P(-1.18<z<0.55) = 0.3790-0.2088

= 0.1702