Math Problem Statement

A certain standardized​ test's math scores have a​ bell-shaped distribution with a mean of 525 and a standard deviation of 110. (b) What percentage of standardized test scores is less than 415 or greater than 635​?

Solution

We are given that the math scores of a standardized test follow a bell-shaped (normal) distribution with:

  • Mean μ=525\mu = 525
  • Standard deviation σ=110\sigma = 110

We need to find the percentage of test scores that are less than 415 or greater than 635.

Steps:

  1. Convert raw scores to Z-scores: The Z-score formula is given by:

Z=XμσZ = \frac{X - \mu}{\sigma}

where:

  • XX is the raw score,
  • μ\mu is the mean, and
  • σ\sigma is the standard deviation.
  1. **Calculate the Z-s

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Math Problem Analysis

Mathematical Concepts

Normal Distribution
Z-scores
Probability

Formulas

Z = (X - μ) / σ

Theorems

Empirical Rule
Standard Normal Distribution

Suitable Grade Level

Grades 10-12