### Home > INT3 > Chapter Ch6 > Lesson 6.2.4 > Problem 6-64

When the principal at Algieres High School started on the job many years ago he believed that over 20% of students are text-messaging at least once a week during class. He believed this was an impediment to effective learning. Students claimed that the actual percentage was much lower and that stricter rules were not necessary. Mrs. Rahil secretly observed her homeroom class very carefully for a week; only 13% of students actually text-messaged during class. Assuming her homeroom was representative of the whole school, Mrs. Rahil’s class did a computer simulation and determined a margin of error of 10%. Is it plausible that the principal was correct and 20% of the whole school was text-messaging? Homework Help ✎

Students can be assumed to be text-messaging 13% ± 10% of the time.