Item: tTableExtendModelOtherRecursive1a
Stimulus:
| Puppy's Age |
Puppy's Weight |
| 1 month |
10 lbs |
| 2 months |
15 lbs |
| 3 months |
19 lbs |
| 4 months |
22 lbs |
| 5 months |
? |
Stem:
John records the weight of his puppy every month
in a chart like the one shown to the left. If the pattern of
the puppy's weight gain continues, how many pounds will
the puppy weigh at 5 months?
Options:
30
27
25
24
Key:
- Observable: 2.
Score: 0;
Evidence Value: 0.
-
Student:Sorry, that's not right. It seems that you tried to add a
common difference to 22, but these sequences are not arithmetic sequences.
There is a different relationship that you need to find.
The correct answer is 24.
-
Teacher:Student saw that the first difference is 5,
and assumed that each weight given is always 5 more pounds than the last
(would choose 27 in this case, because of adding 5 to 22).
- Observable: 1.
Score: 0;
Evidence Value: 0.
-
Student:Sorry, that's not right. For these kinds of problems, you need to find a
pattern between the numbers.
The correct answer is 24.
-
Teacher:Not sure how 30 could be chosen.
- Observable: 3.
Score: 0;
Evidence Value: 0.
-
Student:Sorry, that's not right. It seems that you tried to add a
common difference to 22, but these sequences are not arithmetic sequences.
There is a different relationship that you need to find.
The correct answer is 24.
-
Teacher:Could have chosen 25 if only checked the last difference of 3.
- Observable: 4.
Score: 1;
Evidence Value: 1.
-
Student:Correct, good job!
-
Teacher:The student got this item correct.
Metadata:
Item Node: tTableExtendModelOtherRecursive1a,
Difficulty: 1.
Proficiencies: TableOtherRecurisive,
ExtendOtherRecursive,
ModelOtherRecursive.