Solution: We are given:
Temperature at any random location in a kiln used for manufacturing bricks is normally distributed with mean
standard deviation 
We have to find the percentage of glazed bricks that will discolor. A brick will discolor if the temperature is below 900°f.
Therefore, we have to find 
Using the z score formula, we have:



Now we have to find 
Using the standard normal table, we have:


Therefore, 2.28% of glazed bricks will discolor.