Let's carefully go through the problem and verify the solution step by step for
mean,
median, and
mode of the sequence:
Given Sequence:
19, 12, 9, 5, 8, 5, 25, 8
---
Step 1: Mean
The
mean is the average of all numbers.
$$
\text{Mean} = \frac{\sum x}{N}
$$
Where $ N = 8 $ (total numbers).
Add all values:
$$
19 + 12 + 9 + 5 + 8 + 5 + 25 + 8 =
$$
Break it down:
- 19 + 12 = 31
- 31 + 9 = 40
- 40 + 5 = 45
- 45 + 8 = 53
- 53 + 5 = 58
- 58 + 25 = 83
- 83 + 8 =
91
So,
$$
\text{Mean} = \frac{91}{8} = 11.375
$$
✔ Correct
---
Step 2: Median
To find the median, arrange the numbers in
ascending order:
Original: 19, 12, 9, 5, 8, 5, 25, 8
Sorted:
5, 5, 8, 8, 9, 12, 19, 25
There are 8 numbers → even count.
For even $ N $, the median is the average of the $ \frac{N}{2} $th and $ \left(\frac{N}{2} + 1\right) $th terms.
So:
- $ \frac{8}{2} = 4 $th term →
8
- $ \frac{8}{2} + 1 = 5 $th term →
9
$$
\text{Median} = \frac{8 + 9}{2} = \frac{17}{2} = 8.5
$$
✔ Correct
---
Step 3: Mode
The
mode is the number that appears most frequently.
Look at the sorted list:
5, 5, 8, 8, 9, 12, 19, 25
- 5 → appears
2 times
- 8 → appears
2 times
- All others appear once
Since both
5 and
8 appear twice (and more than any other number), this data set has
two modes.
➡️ This is called a
bimodal distribution.
So,
Mode = 5 and 8
But in some contexts, if no number repeats more than others, we say there is
no mode, but here since two numbers tie for most frequent, they are both modes.
✔ So,
Mode = 5 and 8 (bimodal)
---
Final Answer:
-
Mean: 11.375
-
Median: 8.5
-
Mode: 5 and 8 (bimodal)
---
✔ Summary:
| Measure | Value |
|--------|---------------|
| Mean | 11.375 |
| Median | 8.5 |
| Mode | 5 and 8 |
> Note: The original solution provided only calculated mean and median. It
did not include the mode, which is required by the question. So, to complete the answer, you must add the
mode as shown above.
Let me know if you'd like a visual or table format!
Parent Tip: Review the logic above to help your child master the concept of mean median mode calculation.