In Constructing a 99% Confidence Interval Estimate for the Difference

question 8

Short Answer

In constructing a 99% confidence interval estimate for the difference between the means of two normally distributed populations, where the unknown population variances are assumed not to be equal, summary statistics computed from two independent samples are as follows: $\begin{array}{|l|l|l|}\hline n_{1}=28 & x-\text { bar }_{1}=123 & s_{1}=8.5 \\\hline n_{2}=45 & x-\text { bar }_{2}=105 & s_{2}=12.4 \\\hline\end{array}$ The lower confidence limit is: $$\begin{array} { | l | l | } \hline \text { A. } & 24.485 \\\hline \text { B. } & 11.515 . \\\hline \text { C. } & 13.116 . \\\hline \text { D. } & 22.884 \\\hline\end{array}$$

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Atoll

A ring-shaped coral reef, island, or series of islets surrounding a lagoon, often found in tropical ocean waters.

Meteoroid

Solid object in interplanetary space; distinguished from asteroids by a smaller size.

Volcanic Island

An island formed from the accumulation of material erupted through the crust from a volcanic vent, typically found in oceans.

Subduction

The mechanism in which one tectonic plate slides beneath another, descending into the mantle where the plates come together.