Question

the test scores of the students in four classes are summarized below. answer the questions about them.
class a: the mean score is 119 and the range of scores is 39.
class b: the mean score is 114 and the range of scores is 35.
class c: the mean score is 120 and the range of scores is 33.
class d: the mean score is 115 and the range of scores is 34.
(a) based on the information above, which classs scores have the least variability?
○ class a ○ class b ○ class c ○ class d
(b) based on the information above, which class has the lowest scores on average?
○ class a ○ class b ○ class c ○ class d

Explanation:

Part (a)

Step1: Recall variability and range

Variability in scores can be related to the range (range = max - min). A smaller range means less variability.

Step2: Compare ranges

• Class A: range = 39
• Class B: range = 35
• Class C: range = 33
• Class D: range = 34

The smallest range is 33 (Class C).

Step1: Recall mean represents average

The mean score is the average score of the class. To find the lowest average, we compare the mean scores.

Step2: Compare mean scores

• Class A: mean = 119
• Class B: mean = 114
• Class C: mean = 120
• Class D: mean = 115

The lowest mean is 114 (Class B).

Answer:

C. Class C

Part (b)