Question

School 1 Statistics: Average truancy per student is 8 days per semester with a standard deviation 2.2 and a population of 250 students.
a. What percent of the population is truant more than 9 days?
b. What percent of the population is truant less than 3 days?
c. What percent of the population is truant between 5 and 10 days?
d. What percent of the population is truant between 8.5 and 10 days?
e. What raw score would produce a truancy percent of the top 15% of the students who missed the least amount of school?

Answer 1

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the various Z scores.