Math Problem Statement

The ages of the winners of a cycling tournament are approximately​ bell-shaped. The mean age is

28.628.6

​years, with a standard deviation of

3.43.4

years. The winner in one recent year was

3636

years old.

​(a) Transform the age to a​ z-score.

​(b) Interpret the results.

​(c) Determine whether the age is unusual.

Question content area bottom

Part 1

​(a) Transform the age to a​ z-score.

z equalsz=2.182.18

​(Type an integer or decimal rounded to two decimal places as​ needed.)

Part 2

​(b) Interpret the results.

An age of

3636

is

enter your response here

standard​ deviation(s)

the mean.

​(Type an integer or decimal rounded to two decimal places as​ needed

Solution

To solve this problem, let's go through each part step by step.

Part 1: Transform the age to a z-score.

The formula for calculating a z-score is:

z=(Xμ)σz = \frac{(X - \mu)}{\sigma}

Where:

  • XX is the value (age of the winner)
  • μ\mu is the mean
  • σ\sigma is the standard deviation

Given:

  • X=36X = 36
  • μ=28.6\mu = 28.6
  • σ=3.4\sigma = 3.4

Now, substituting the values into the formula:

z=(3628.6)3.4=7.43.42.18z = \frac{(36 - 28.6)}{3.4} = \frac{7.4}{3.4} \approx 2.18

So the z-score is approximately 2.18.

Part 2: Interpret the results.

The z-score of 2.18 means that the age of 36 years is 2.18 standard deviations above the mean age of the winners.

Part 3: Determine whether the age is unusual.

In general, a z-score greater than 2 or less than -2 is considered unusual in a bell-shaped distribution. Since 2.18 is greater than 2, the age of 36 years can be considered unusual.

Summary of Answers:

  • (a) The z-score is 2.18.
  • (b) An age of 36 is 2.18 standard deviations above the mean.
  • (c) The age is unusual because it is more than 2 standard deviations from the mean.

Would you like to dive deeper into any of these parts, or do you have any other questions? Here are some related questions to consider:

  1. What does it mean for a distribution to be bell-shaped?
  2. How can z-scores be used in other contexts?
  3. What is the significance of the mean and standard deviation in a dataset?
  4. How do you interpret negative z-scores?
  5. Can z-scores help identify outliers in a dataset?

Tip: Always consider the context of the data when interpreting z-scores, as the implications can vary based on the field of study.

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Math Problem Analysis

Mathematical Concepts

Statistics
Z-Scores
Standard Deviation
Normal Distribution

Formulas

z = (X - μ) / σ

Theorems

Empirical Rule

Suitable Grade Level

Grades 10-12