(A) Construct a 90% Confidence Interval Estimate of the Mean

question 64

Essay

(A) Construct a 90% confidence interval estimate of the mean family dental expenses for all employees of this corporation.
(B) What assumption about the population distribution must be made to answer (A)?
(C) Interpret the 90% confidence interval constructed in (A).
(D) Suppose you used a 95% confidence interval in (A). What would be your answer?
(E) Suppose the fourth value were 593 instead of 93. What would be your answer to (A)? What effect does this change have on the confidence interval?
(F) Construct a 90% confidence interval estimate for the standard deviation of family dental expenses for all employees of this corporation.
(G) Interpret the 90% confidence interval constructed in (E).

---

Definitions:

Statistical Inference

The process of drawing conclusions about a population’s parameters based on a sample taken from the population.

Descriptive Statistics

Statistical techniques used to summarize, show, and describe the basic features of data sets, providing simple summaries about the sample and measures.

Ratio Scale

A scale where there is a true zero point, allowing for the measurement of ratios between data points.

Proportion

A statistical measure expressing the fraction of a quantity within a whole.