Ask questions, share knowledge, and connect with a vibrant community on IDNLearn.com. Our platform is designed to provide reliable and thorough answers to all your questions, no matter the topic.

Polina's math scores are shown in the table.

\begin{tabular}{|l|l|l|l|l|l|}
\hline \multicolumn{6}{|c|}{ Polina's Math Scores } \\
\hline Math Scores & 72 & 65 & 75 & 88 & 90 \\
\hline
\end{tabular}

What is the mean absolute deviation of her math scores?

A. 5.4
B. 6.4
C. 7.8
D. 8.8


Sagot :

To find the mean absolute deviation (MAD) of Polina's math scores, we follow these steps:

1. List the Math Scores: Polina's math scores are 72, 65, 75, 88, and 90.

2. Calculate the Mean (Average) Score:
[tex]\[ \text{Mean Score} = \frac{\sum \text{Math Scores}}{\text{Number of Scores}} \][/tex]
[tex]\[ \text{Mean Score} = \frac{72 + 65 + 75 + 88 + 90}{5} = \frac{390}{5} = 78 \][/tex]

3. Calculate the Absolute Deviations from the Mean:
The absolute deviation for each score is the absolute difference between the score and the mean score.
[tex]\[ |72 - 78| = 6 \][/tex]
[tex]\[ |65 - 78| = 13 \][/tex]
[tex]\[ |75 - 78| = 3 \][/tex]
[tex]\[ |88 - 78| = 10 \][/tex]
[tex]\[ |90 - 78| = 12 \][/tex]

So, the absolute deviations are 6, 13, 3, 10, and 12.

4. Calculate the Mean of the Absolute Deviations:
[tex]\[ \text{Mean Absolute Deviation (MAD)} = \frac{\sum \text{Absolute Deviations}}{\text{Number of Deviations}} \][/tex]
[tex]\[ \text{Mean Absolute Deviation (MAD)} = \frac{6 + 13 + 3 + 10 + 12}{5} = \frac{44}{5} = 8.8 \][/tex]

Based on these calculations, the mean absolute deviation of Polina's math scores is [tex]\(\boxed{8.8}\)[/tex].