Item: tExplicitArithmetic3b
Stem:
The first four terms of an arithmetic sequence are given below.
Choose the algebraic expression that represents the nth
term in this sequence.
-10, -19, -28, -37, . . .
Options:
9n - 10
-9n
9n - 1
-10n - 9
-9n - 1
Key:
- Observable: 5.
Score: 1;
Evidence Value: 1.
-
Student:Right! The expression you selected, -9n - 1, is correct.
-
Teacher:The student got this item correct.
- Observable: 1.
Score: 0;
Evidence Value: 0.
-
Student:Sorry, the expression you selected, 9n - 10, is incorrect. The sequence in the question is: -10, -19, -28, -37,... But the expression you selected describes the sequence: -1, 8, 17, 26,...
-
Teacher:The student did not get this item right.
- Observable: 2.
Score: 0;
Evidence Value: 0.
-
Student:Sorry, the expression you selected, -9n, is incorrect. The sequence in the question is: -10, -19, -28, -37,... But the expression you selected describes the sequence: -9, -18, -27, -36,...
-
Teacher:The student did not get this item right.
- Observable: 3.
Score: 0;
Evidence Value: 0.
-
Student:Sorry, the expression you selected, 9n - 1, is incorrect. The sequence in the question is: -10, -19, -28, -37,... But the expression you selected describes the sequence: 8, 17, 26, 35,...
-
Teacher:The student did not get this item right.
- Observable: 4.
Score: 0;
Evidence Value: 0.
-
Student:Sorry, the expression you selected, -10n - 9, is incorrect. The sequence in the question is: -10, -19, -28, -37,... But the expression you selected describes the sequence: -19, -29, -39, -49,...
-
Teacher:The student did not get this item right.
Metadata:
Item Node: tExplicitArithmetic3b,
Difficulty: 3.
Proficiencies: ExplicitArithmetic.