Mean and median The figure displays two density curves that model different

distributions of quantitative data. Identify the location of the mean and median by letter for each graph. Justify your answers.

Short Answer

Expert verified

Part (a) Mean is located at Aand the median is located at A

Part (b) Mean is located at A and the median is also located at B

Step by step solution

01

Part (a) Step 1: Given information

02

Part (a) Step 2: Concept

Neither of these transformations changes the shape of the distribution.

03

Part (a) Step 3: Explanation

The graph on the left of A is the inverse of the graph on the right. The distribution is thus symmetric.

Both the median and the mean should be at the center of the distribution for the distribution to be symmetric (at the point A).

As a result, A stands for both the mean and the median.

04

Part (b) Step 1: Given information

05

Part (b) Step 2: Explanation

The distribution's apex is to the right, and the distribution is skewed to the left, with a tail of more unusual values to the left in the graph.

Because the median is resistant while the mean is not, the mean is more influenced by the left-skewed distribution's extremely high values.

Because both the mean and the median are influenced by unusually high values in the left-skewed distribution, one measure impacts more than the other, neither the median nor the mean is predicted to reside at the distribution's peak. The mean is lower than the median, and neither is at its highest point.

As a result, A denotes the mean and B denotes the median.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Big sharks Here are the lengths (in feet) of 44 great white sharks:

A dot plot of the data and summary statistics are shown below. Is this distribution of shark length approximately Normal? Justify your answer based on the graph and the 68–95–99.7 rule.

nMeanSDMinQ1MedQ3Max
44155862.559.413.5515.7517.222.8

Batter up! Refer to Exercise 48A player with a batting average below 0.200 is at risk of sitting on the bench during important games. About what percent of players are at risk?

SAT versus ACT Eleanor scores 680 on the SAT Mathematics test. The distribution of SAT Math scores is symmetric and single-peaked with mean 500 and a standard deviation 100 Gerald takes the American College Testing (ACT) Mathematics test and scores 29ACT scores also follow asymmetric, single-peaked distribution—but with mean 21 and standard deviation of 5 Find the standardized scores for both students. Assuming that both tests measure the same kind of ability, who has the higher score?

Jorge’s score on Exam 1in his statistics class was at the 64thpercentile of the scores for all students. His score falls

a. between the minimum and the first quartile.

b. between the first quartile and the median.

c. between the median and the third quartile.

d. between the third quartile and the maximum.

e. at the mean score for all students.

IQ test scores Scores on the Wechsler Adult Intelligence Scale (a standard IQ test) for the 20to 34age group are approximately Normally distributed with μ=110and σ=25. For each part, follow the fourstep process.

(a) At what percentile is an IQ score of 150?

(b) What percent of people aged 20to 34have IQs between 125and 150?

(c) MENSA is an elite organization that admits as members people who score in the top 2%on IQ tests. What score on the Wechsler Adult Intelligence Scale would an individual have to earn to qualify for MENSA membership?

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free