Back to Distributions of random variables

Exercise 47

Avg difficulty 3.0

Heights of 10 year olds, Part III. Heights of 10 year olds, regardless of gender, closely follow a normal distribution with mean 55 inches and standard deviation 6 inches.

  1. What fraction of 10 year olds are taller than 76 inches?

  2. If there are 2,000 10 year olds entering Six Flags Magic Mountain in a single day, then compute the expected number of 10 year olds who are at least 76 inches tall. (You may assume the heights of the 10-year olds are independent.)

  3. Using the binomial distribution, compute the probability that 0 of the 2,000 10 year olds will be at least 76 inches tall.

  4. The number of 10 year olds who enter Six Flags Magic Mountain and are at least 76 inches tall in a given day follows a Poisson distribution with mean equal to the value found in part (2). Use the Poisson distribution to identify the probability no 10 year old will enter the park who is 76 inches or taller.

Diez, Barr & Çetinkaya-Rundel, OpenIntro Statistics, Distributions of random variables, End-of-Chapter Exercises, Exercise 47

AI Tutor

Adapted from OpenIntro Statistics © 2019 David Diez, Mine Çetinkaya-Rundel & Christopher D. Barr. Licensed under CC BY-SA 3.0. Source: OpenIntro Statistics. Imported at revision fee2509.