In Order to Compare the Means of Two Populations, Independent $\begin{array}{ll}\text { Sample 1 } & \text { Sample 2 } \\\bar{x}_{1}=7,123 & \bar{x}_{2}=6,957 \\s_{1}=175 & s_{2}=225\end{array}$

question 16

Essay

In order to compare the means of two populations, independent random samples of 144 observations are selected from each population with the following results.

$\begin{array}{ll}\text { Sample 1 } & \text { Sample 2 } \\\bar{x}_{1}=7,123 & \bar{x}_{2}=6,957 \\s_{1}=175 & s_{2}=225\end{array}$

Use a 95\% confidence interval to estimate the difference between the population means $\left( \mu _ { 1 } - \mu _ { 2 } \right)$ . Interpret the confidence interval.

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Definitions:

Bark

External part of a tree, containing cork, cork cambium, and phloem.

Casparian Strip

A band of cell wall material found in plant roots that helps control the movement of water and nutrients between the soil and the vascular system.

Suberin

A waxy hydrophobic substance found in the cell walls of plants, acting as a barrier to water and solute movement.

Lignin

A complex organic polymer found in the cell walls of many plants, making them rigid and woody, and contributing to their structural support.