# Standardize the data values to find the percentage of values

Standardize the data values to find the percentage of values in the described area. Show the z-score of each value, and the percentage asked in the question. Questions are listed here:The average daily purchase of raw materials of some factories was \$125,000 and the standard deviation was \$10,000. Assuming the distribution to be normal, what percentage of factories have purchases of raw materials between \$100,000 and \$135,000?The results of a recent aptitude test given to high school students were normally distributed with a mean of 500 and a standard deviation of 100. What percentage of students received scores exceeding 700?The scoring of modern IQ tests is such that Intelligence Quotients (IQs) have a normal distribution with a mean of 100 and a standard deviation of 15. What percent of people have an IQ less than 80?The time spent by students working on a project is a normal distribution. It has a mean of 12 hours and a standard deviation of 4 hours. What is the proportion of the amount of time spent on the project is between 9 and 13 hours?