The income distribution of workers in a certain factory was found to be normal with mean of $. 5000 and standard deviation equal to $. 500. There were 228 persons getting above $. 6000. How many...

Extracted text: The income distribution of workers in a certain factory was found to be normal with mean of $. 5000 and standard deviation equal to $. 500. There were 228 persons getting above $. 6000. How many persons were there in all? (Area under the standard normal curve between height at 0 and 2 is 0.4772).