Chapter 4, Problem 24P

BuyFind*arrow_forward*

8th Edition

Frederick J Gravetter + 1 other

ISBN: 9781133956570

Textbook Problem

In the previous problem we noted that the differences in cognitive skills tend to be bigger among older people than among younger people. These differences are often called diversity. Similarly, the differences in performance from trial to trial for the same person are often called consistency. Research in this area suggests that consistency of performance seems to decline as people age. A study by Wegesin and Stem (2004) found lower consistency (more variability) in the memory performance scores for older women than for younger women. The following data represent memory scores obtained for two women, one older and one younger, over a series of memory trials.

**a.** Calculate the variance of the scores for each woman.

**b.** Are the scores for the younger woman more consistent (less variable)?

Younger |
Older |

8 | 7 |

6 | 5 |

6 | 8 |

7 | 5 |

8 | 7 |

7 | 6 |

8 | 8 |

8 | 5 |

**(a)**

To determine

**To Find:** The variance scores for each group.

Explanation

**Given info:**

The information shows the memory scores of the younger women and older women.

**Calculation:**

The formula for calculating the mean is,

The formula for calculating the variance is,

*For younger women:*

The mean for younger women is,

The variance for younger women is,

**(b)**

To determine

**To find:** The reason that the younger woman is more consistent than the older woman.

Essentials Of Statistics

Understanding Basic Statistics

Statistics for The Behavioral Sciences (MindTap Course List)

Probability and Statistics for Engineering and the Sciences

Essentials of Statistics for The Behavioral Sciences (MindTap Course List)

Calculus (MindTap Course List)

Calculus: Early Transcendentals

Elements Of Modern Algebra

Elementary Geometry For College Students, 7e

Single Variable Calculus: Early Transcendentals, Volume I

Calculus: Early Transcendental Functions

Intermediate Algebra

Trigonometry (MindTap Course List)

Finite Mathematics and Applied Calculus (MindTap Course List)

Contemporary Mathematics for Business & Consumers

Precalculus: Mathematics for Calculus (Standalone Book)

Finite Mathematics

Single Variable Calculus: Early Transcendentals

Elementary Technical Mathematics

Mathematical Excursions (MindTap Course List)

Calculus: An Applied Approach (MindTap Course List)

Single Variable Calculus

Multivariable Calculus

Mathematical Applications for the Management, Life, and Social Sciences

Applied Calculus

Applied Calculus for the Managerial, Life, and Social Sciences: A Brief Approach

Calculus: Early Transcendental Functions (MindTap Course List)

Calculus of a Single Variable

Finite Mathematics for the Managerial, Life, and Social Sciences

Introduction To Statistics And Data Analysis

Study Guide for Stewart's Single Variable Calculus: Early Transcendentals, 8th

Study Guide for Stewart's Multivariable Calculus, 8th

Elementary Geometry for College Students