| Rater | Correctness P/E/N | Conceptual Understanding | Processes & Strategies | Communication | Verification |
| mh | P | 4 | 4 | 4 | 4 |
Name Melody
Benchmark III, Grade Level 6, Strand - Statistics and Probability
Teacher Mrs. Huffman Date Sept. 25, 1998
Problem: For the set (3, 4, 5, 8, x) the mean, median and mode all have the same value. What is the value of x?
Melody's response:
What I need to do to solve this problem: I need to find out the averages (mean) by adding all the numbers then dividing by 5. Then I need to find the mode by seeing if the x is any one of the other numbers. Then I need to find out the median, or middle.
How I solved this problem: Guess and check.
| 3+4+5+8+3 = 23
23/5 = 4 r3, (doesn't work) |
3+4+5+8+4 = 24
24/5 = 4 r4, (doesn't work) |
3+4+5+8+5 = 25
25/5 = 5, this could be a mean and a mode |
3+4+5+8+8 = 28
28/5 = 5 r3, (doesn't work) |
In order, 3, 4, 5, 5, 8. So 5 is the median.
Mode could be 5.
Answer: x = 5
How I checked my work: I know 5 is the mean because it goes in equally with the other numbers. I know 5 is the median because if all the numbers were in order, 5 would be the middle number. I know 5 is the mode because if there was another 5, it would be the only number that is listed twice.