Question

mean = \frac{35 + 10 + 25 + 42 + 19}{5} = 27\
step 2: find each absolute deviation.\
\
\\ \\ \\ \\ \\ \\ 8, 11, 4, 15, 8\
step 3: find the mean absolute deviation.\
\
\\ \\ \\ \\ \\ \\ mad = \frac{8 + 11 + 4 + 15}{5} = 9.5\
what is doras error?\
\bigcirc dora should have divided by 4 when finding the mean.\
\bigcirc dora found the absolute deviation of 35 incorrectly.\
\bigcirc dora used only four numbers in finding the mean.\
\bigcirc dora used only four numbers in finding the mean absolute deviation.

Explanation:

Step1: Verify MAD calculation

The absolute deviations are 8, 11, 4, 15, 8 (5 values). Dora's formula uses only 4 values: $\frac{8+11+4+15}{5}$. She omitted the final 8.

Step2: Evaluate each option

• Option1: There are 5 data points, dividing by 4 is wrong.
• Option2: No info on 35's deviation is given.
• Option3: Mean calculation used 5 values (divided by 5).
• Option4: Dora excluded one absolute deviation value.

Answer:

Dora used only four numbers in finding the mean absolute deviation.