Construct a Confidence Interval For $\mu _ { \mathrm { d } }$

question 89

Multiple Choice

Construct a confidence interval for $\mu _ { \mathrm { d } }$ , the mean of the differences d for the population of paired data. Assume that the
population of paired differences is normally distributed.
-Ten different families are tested for the number of gallons of water a day they use before and after viewing a conservation video. Construct a $90 \%$ confidence interval for the mean of the differences.
$\begin{array}{lllllllllll}\text { Before } & 33 & 33 & 38 & 33 & 35 & 35 & 40 & 40 & 40 & 31 \\\hline \text { After } & 34 & 28 & 25 & 28 & 35 & 33 & 31 & 28 & 35 & 33\end{array}$

• A) \(1.5 < \mu _ { \mathrm { d } } < 8.1\)
• B) \(3.8 < \mu _ { \mathrm { d } } < 5.8\)
• C) \(1.8 < \mu _ { \mathrm { d } } < 7.8\)
• D) \(2.5 < \mu _ { \mathrm { d } } < 7.1\)

---

Definitions:

England

A country that is part of the United Kingdom, known for its rich history, cultural heritage, and as the birthplace of the English language.

United States

A country in North America consisting of 50 states and a federal district, known for its diverse culture and significant global influence.

Sierra Club

An environmental organization in the United States committed to protecting the natural world and addressing climate change.

Clifford Sifton

A Canadian politician known for his role in promoting immigration to settle the western provinces of Canada, significantly shaping the nation's demographic and agricultural expansion.