# Math Help - Z Scores

1. ## Z Scores

Because of the populaity of movies as an entertainment medium for college students, you plan to do a national study of the average cost of a movie ticket. If you assume that the standard deviation of the population = $0.50, what samle size would you have to take to be 95% confident that your estimate was within$0.25 of the true mean ticket prices?

2. Originally Posted by jax760
Because of the populaity of movies as an entertainment medium for college students, you plan to do a national study of the average cost of a movie ticket. If you assume that the standard deviation of the population = $0.50, what samle size would you have to take to be 95% confident that your estimate was within$0.25 of the true mean ticket prices?
Solve $0.25 = 1.96 \left( \frac{0.50}{\sqrt{n}} \right)$ for $n$.