The mean test scores with standard deviations of four English classes are given below.

| Class | Mean | Standard Deviation |
| :-------- | :------- | :------------------- |
| Mrs. Jones | 89 | 1.9 |
| Mrs. Rijo | 82 | 1.4 |
| Mr. Phan | 73 | 3.4 |
| Mrs. Scott | 90 | 6.1 |

Which statement is most likely to be true?
A. The scores of Mrs. Scott's class are the closest to the class mean.
B. The scores of Mr. Phan's class are the closest to the class mean.
C. The scores of Mrs. Jones's class are the closest to the class mean.
D. The scores of Mrs. Rijo's class are the closest to the class mean.

Standard deviation measures the spread of data around the mean.
Smaller standard deviation indicates data points are closer to the mean.
Mrs. Rijo's class has the smallest standard deviation: 1.4 .
Therefore, Mrs. Rijo's class scores are closest to the mean. The scores of Mrs. Rijo’s class are the closest to the class mean. ​

Explanation

Analyze the problem and data We are given the mean and standard deviation of test scores for four English classes. The standard deviation tells us how spread out the data is from the mean. A smaller standard deviation means the data points are closer to the mean. We need to find the smallest standard deviation among the four classes to determine which class has scores closest to the mean.

Identify the standard deviations The standard deviations for the four classes are:



Mrs. Jones: 1.9
Mrs. Rijo: 1.4
Mr. Phan: 3.4
Mrs. Scott: 6.1 We need to find the smallest of these values.


Compare and find the smallest standard deviation Comparing the standard deviations, we see that Mrs. Rijo's class has the smallest standard deviation (1.4). This means that the scores in Mrs. Rijo's class are the closest to the class mean.

Conclusion Therefore, the scores of Mrs. Rijo's class are the closest to the class mean.


Examples
In a classroom setting, understanding standard deviation helps teachers analyze the spread of student scores around the average. A smaller standard deviation indicates that the scores are more consistent and closer to the average, which can inform teaching strategies and identify students who may need additional support. For example, if two classes have the same average score, but one has a smaller standard deviation, it means that the scores in that class are more tightly clustered around the average, indicating more consistent performance among the students.

Answered by GinnyAnswer | 2025-07-03

Mrs. Rijo's class has the smallest standard deviation of 1.4, indicating that their scores are closest to the class mean. Therefore, the answer is D: The scores of Mrs. Rijo's class are the closest to the class mean.
;

Answered by Anonymous | 2025-07-04