(A) Construct a 95% Confidence Interval for the Average Width

question 8

Essay

(A) Construct a 95% confidence interval for the average width of an elevator rail. Do we need to assume that the width of elevator rails follows a normal distribution?
(B) How large a sample of elevator rails would we have to measure to ensure that we could estimate, with 95% confidence, the average diameter of an elevator rail within 0.01 inch?

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Definitions:

Analysis Period

The specific time frame over which financial or operational performance is analyzed and evaluated.

Base Period

A specific time period used as a benchmark or point of reference for comparing financial or economic data over time.

Horizontal Analysis

A financial analysis technique that compares line items in financial statements over multiple periods to identify trends.

Financial Data Across Time

Refers to historical financial statistics, such as revenue, profits, and expenses, tracked over different periods to analyze trends and performance.