91Ó°ÊÓ

$t-$When using the interval process on the supplied data, we wish to get the $90\%$ confidence interval of the population mean $\mathrm{μ}$, therefore $(1880.1,2049.4)$ is the $90\%$ confidence interval of the population mean $\mathrm{μ}$

[Using MINITAB]

i.e., we may be $90\%$ certain that the average price of all half-carat diamonds, $\mathrm{μ}$, is between $\$1880.1$ and $$ 2049.4$.

Now, draw the probability plot for the given data.

Now, construct the box plot for the given data.

Now, construct the histogram for the given data.

Create the stem-and-leaf for the supplied data collection now.

Stem-and-Leaf Display: PRICE

Leaf Unit $=10$

Stem Leaf

$$\begin{gathered} 1144 \\ 115 \\ 2167 \\ 3171 \\ 51827 \\ \left(6\right)19448899 \\ 720377 \\ 42104 \\ 2223 \\ 1231 \end{gathered}$$

No, the $t-$interval technique is not appropriate for the data. Because the sample is of a reasonable size and the graphical representations reveal that the data contains an outlier (observation $1442$).