Chapter 8, Problem T8.12SPT

a)

To determine

To interpret: The confidence interval.

Explanation of Solution

Given:

The confidence level is 95% Confidence interval = (317.64, 394.56)

Formula used:

The formulas to compute the margin of error and point estimate are:

  $\begin{array}{l}\text{Point estimate}=\frac{\text{Upper limit}+\text{Lower limit}}{2}\\ \text{Margin of error}=\frac{\text{Upper limit}-\text{Lower limit}}{2}\end{array}$

The range is provided by the confidence interval in which the population parameter is likely to fall in.

There is 95% possibility that mean number of licks fall between 317.64 and 394.56.

b)

To determine

To find: The point estimate and the margin of error.

Answer to Problem T8.12SPT

The values are 356.1 and 38.5.\

Explanation of Solution

The point estimate and margin of error are calculated as:

  $\begin{array}{c}\text{Point estimate}=\frac{\text{Upper limit}+\text{Lower limit}}{2}\\ =\frac{394.56+317.64}{2}\\ =356.1\end{array}$

  $\begin{array}{c}\text{Margin of error}=\frac{\text{Upper limit}-\text{Lower limit}}{2}\\ =\frac{394.56-317.64}{2}\\ =38.5\end{array}$

Thus, the required values are 356.1 and 38.5.