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Chapter 7

Student Lecture Notes

7-1

Business Statistics: A Decision-Making Approach
6th Edition

Chapter 7 Estimating Population Values

Fundamentals of Business Statistics – Murali Shanker

Chap 7-1

Confidence Intervals
Content of this chapter Confidence Intervals for the Population Mean, μ when Population Standard Deviation σ is Known when Population Standard Deviation σ is Unknown

Determining the Required Sample Size

Fundamentals of Business Statistics – Murali Shanker

Chap 7-2

Fundamentals of Business Statistics – Murali Shanker

Chapter 7

Student Lecture Notes

7-2

Confidence Interval Estimation for μ
Suppose you are interested in estimating the average amount of money a Kent State Student (population) carries. How would you find out?

Fundamentals of Business Statistics – Murali Shanker

Chap 7-3

Point and Interval Estimates
A point estimate is a single number, a confidence interval provides additional information about variability

Lower Confidence Limit

Point Estimate Width of confidence interval

Upper Confidence Limit

Fundamentals of Business Statistics – Murali Shanker

Chap 7-4

Fundamentals of Business Statistics – Murali Shanker

Chapter 7

Student Lecture Notes

7-3

Estimation Methods
Point Estimation
Provides single value Based on observations from 1 sample Gives no information on how close value is to the population parameter

Interval Estimation
Provides range of values Based on observations from 1 sample Gives information about closeness to unknown population parameter Stated in terms of “level of confidence.” To determine exactly requires what information?

Fundamentals of Business Statistics – Murali Shanker

Chap 7-5

Estimation Process
Random Sample Population
(mean, μ, is unknown) Sample Mean x = 50 I am 95% confident that μ is between 40 & 60.

Fundamentals of Business Statistics – Murali Shanker

Chap 7-6

Fundamentals of Business Statistics –

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