In the spring semester 2017, students in one section of math determined that the
ID: 3362789 • Letter: I
Question
In the spring semester 2017, students in one section of math determined that the length of movies at the cinema was normally distributed with a mean of 148 minutes and a standard deviation of 19 minutes. Find the third quartile and interpret it. Round to the nearest tenth. Which one below is correct?
75 minutes; Three-fourths of the movie lengths fall below 75 minutes.
160.8 minutes; Three-fourths of the movie lengths fall below 160.8 minutes.
160.8; Three-fourths of the movies last 160.8 minutes.
75 minutes; Three-fourths of the movies last 75 minutes.
75 minutes; Three-fourths of the movie lengths fall below 75 minutes.
160.8 minutes; Three-fourths of the movie lengths fall below 160.8 minutes.
160.8; Three-fourths of the movies last 160.8 minutes.
75 minutes; Three-fourths of the movies last 75 minutes.
Explanation / Answer
= 148 = 19 z for 75% = 0.6745.
x = + z
= 148 + 0.6745 * 19
= 160.8 minutes.
Three fourths of the movie lengths fall below 160.8 minutes.