The monthly mean salaries and standard deviations of four college students are given below.

\begin{tabular}{|c|c|c|}
\hline
Student & Mean & Standard Deviation \\
\hline
Clarissa & \[tex]$345 & 12.53 \\
\hline
Abi & \$[/tex]598 & 8.99 \\
\hline
Kaila & \[tex]$812 & 15.29 \\
\hline
Shenika & \$[/tex]208 & 7.67 \\
\hline
\end{tabular}

Which statement must be true?

A. The monthly salary of Shenika is less spread out than the monthly salary of Clarissa.

B. The monthly salary of Kaila is less spread out than the monthly salary of Abi.

C. The monthly salary of Abi is less spread out than the monthly salary of Shenika.

D. The monthly salary of Clarissa is less spread out than the monthly salary of Abi.



Answer :

Let's examine the given statements and determine which one must be true based on the provided standard deviations:

1. The monthly salary of Shenika is less spread out than the monthly salary of Clarissa.
- Shenika's standard deviation: [tex]\(7.67\)[/tex]
- Clarissa's standard deviation: [tex]\(12.53\)[/tex]

We compare [tex]\(7.67 < 12.53\)[/tex]:
- This statement is TRUE.

2. The monthly salary of Kaila is less spread out than the monthly salary of Abi.
- Kaila's standard deviation: [tex]\(15.29 \)[/tex]
- Abi's standard deviation: [tex]\(8.99 \)[/tex]

We compare [tex]\(15.29 < 8.99\)[/tex]:
- This statement is FALSE.

3. The monthly salary of Abi is less spread out than the monthly salary of Shenika.
- Abi's standard deviation: [tex]\(8.99\)[/tex]
- Shenika's standard deviation: [tex]\(7.67\)[/tex]

We compare [tex]\(8.99 < 7.67\)[/tex]:
- This statement is FALSE.

4. The monthly salary of Clarissa is less spread out than the monthly salary of Abi.
- Clarissa's standard deviation: [tex]\(12.53\)[/tex]
- Abi's standard deviation: [tex]\(8.99\)[/tex]

We compare [tex]\(12.53 < 8.99\)[/tex]:
- This statement is FALSE.

From the above analysis:
- Statement 1 is true.
- Statements 2, 3, and 4 are false.

Therefore, the statement that must be true is the first one:
"The monthly salary of Shenika is less spread out than the monthly salary of Clarissa."