3rd Edition

ISBN: 9781260707458

Author: Navidi

Publisher: MCGRAW-HILL CUSTOM PUBLISHING

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A new framework of data analysis where the new statistical methods are used for interpreting the results and analyzing the data is known as estimation in statistics.

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Textbook Question

Chapter 7.3, Problem 29E

Annual income: The mean annual income for people in a certain city (in thousands of dollars) is 42, with a standard deviation of 30. A pollster draws a sample of 90 people to interview.

What is the probability that the sample mean income is less than 38?
What is the probability that the sample mean Income is between 40 and 45?
Find the 60th percentile of the sample mean.
Would it be unusual for the sample mean to be less than 35?
Can you tell whether it would be unusual for an individual to have an income less than 35? Explain.

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.

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Chapter 7.3, Problem 28E

Chapter 7.3, Problem 30E

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Chapter 7 Solutions

ELEMENTARY STATISTICS(LL)(FD)

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Solution Summary: The author calculates the probability of the sample mean being less than 38 thousands of dollars, and the standard deviation for a sample of 90 people.

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