Every week, the programming office at an FM radio station reviewed unsolicited letters from listeners who were expressing comments on the station' s programs  One week, the station received 50 letters with favorable comments about the station' s news reporting and music selection and 10 letters with unfavorable comments on the station' s new movie review segment of the evening program  Faced with this information, the programming director assumed that if some listeners did not like the movie review segment, then there must be other listeners who did like it
Ttherefore, he decided to continue the movie review segment of the evening program
He could not properly infer from the fact that some listeners did not like the movie review segment that some others did.