Statistics

1. 128 students were asked how much they spent on a movie ticket at the movie theater. The national average amount spent on a ticket at the movie theater is $14 with a standard deviation of $6. What is the probability that the random sample of students will give a result within $0.01 of the true value?

2. The average number of students per classroom is 35, with a standard deviation of 5. If 44 classrooms were sampled, how likely is it that the sample averaged fewer than 33.5 students?

3. The average number of text messages sent per day is 30 with a standard deviation of 10. If 117 people are surveyed, what is the probability that the sample sends less than 30.92 text messages per day?