The table shows the length, in inches, of fish in a pond.

\begin{tabular}{|l|l|l|l|}
\hline 15 & 18 & 8 & 22 \\
\hline 7 & 15 & 10 & 18 \\
\hline
\end{tabular}

Determine if the data contains any outliers. If so, list the outliers.

A. There is an outlier at 22.
B. There is an outlier at 7.
C. There are outliers at 7 and 22.
D. There are no outliers.



Answer :

Alright, let's systematically determine if the given data set contains any outliers. Here's a step-by-step explanation:

1. List the Available Data:
The table shows the lengths of fish in a pond:
[tex]\[ 15, 18, 8, 22, 7, 15, 10, 18 \][/tex]

2. Sort the Data:
First, we sort the data in ascending order:
[tex]\[ 7, 8, 10, 15, 15, 18, 18, 22 \][/tex]

3. Determine the Quartiles:
- First Quartile (Q1): This is the median of the first half of the data (not including the median if the number of data points is odd).
[tex]\[ \text{First half of data: } 7, 8, 10, 15 \][/tex]
The median or Q1 of this subset is halfway between 8 and 10:
[tex]\[ Q1 = 9.5 \][/tex]

- Third Quartile (Q3): This is the median of the second half of the data (not including the median if the number of data points is odd).
[tex]\[ \text{Second half of data: } 15, 18, 18, 22 \][/tex]
The median or Q3 of this subset is halfway between 18 and 18:
[tex]\[ Q3 = 18.0 \][/tex]

4. Calculate the Interquartile Range (IQR):
[tex]\[ IQR = Q3 - Q1 = 18.0 - 9.5 = 8.5 \][/tex]

5. Determine the Bounds for Outliers:
- Lower Bound: Any data point below the lower bound is considered an outlier.
[tex]\[ \text{Lower Bound} = Q1 - 1.5 \times IQR = 9.5 - 1.5 \times 8.5 = -3.25 \][/tex]
Since the length of fish cannot be negative, any reasonable positive fish length will not be considered a lower outlier in this context.

- Upper Bound: Any data point above the upper bound is considered an outlier.
[tex]\[ \text{Upper Bound} = Q3 + 1.5 \times IQR = 18.0 + 1.5 \times 8.5 = 30.75 \][/tex]

6. Identify the Outliers:
We now check the fish lengths against these bounds:
[tex]\[ \text{Fish lengths: } 7, 8, 10, 15, 15, 18, 18, 22 \][/tex]
None of these values lie below the lower bound of -3.25 or above the upper bound of 30.75.

Therefore, there are no outliers among the fish lengths in the given dataset.

The correct answer is:
```
There are no outliers.
```