Based on the two data sets given below, which of the following statements are true? Select two that apply.

Data set A: 4, 5, 6, 12, 13.
Data set B: 4, 5, 7, 9, 10.
A. Data set A has a smaller standard deviation than Data set B.
B. Data set A has a larger mean than data set B.
C. Data set A has a larger standard deviation than Data set B.
D. Data set A has the same mean as Data set B.

1 answer

To evaluate the statements based on Data Set A (4, 5, 6, 12, 13) and Data Set B (4, 5, 7, 9, 10), we need to calculate the means and the standard deviations of both data sets.

Step 1: Calculate the means.

For Data Set A:

  • Mean (A) = (4 + 5 + 6 + 12 + 13) / 5 = 40 / 5 = 8

For Data Set B:

  • Mean (B) = (4 + 5 + 7 + 9 + 10) / 5 = 35 / 5 = 7

Step 2: Compare the means.

  • Mean of A: 8
  • Mean of B: 7

So, Data Set A has a larger mean than Data Set B.

Step 3: Calculate the standard deviations.

For Data Set A:

  1. Find the variance:
    • Mean = 8
    • Variance = [(4-8)² + (5-8)² + (6-8)² + (12-8)² + (13-8)²] / 5
    • = [16 + 9 + 4 + 16 + 25] / 5
    • = 70 / 5 = 14
  2. Standard deviation = √14 ≈ 3.74

For Data Set B:

  1. Find the variance:
    • Mean = 7
    • Variance = [(4-7)² + (5-7)² + (7-7)² + (9-7)² + (10-7)²] / 5
    • = [9 + 4 + 0 + 4 + 9] / 5
    • = 26 / 5 = 5.2
  2. Standard deviation = √5.2 ≈ 2.28

Step 4: Compare the standard deviations.

  • Standard deviation of A: ≈ 3.74
  • Standard deviation of B: ≈ 2.28

Data set A has a larger standard deviation than Data set B.

Conclusion: Based on our calculations:

  • Statement A (Data set A has a smaller standard deviation than Data set B) is false.
  • Statement B (Data set A has a larger mean than data set B) is true.
  • Statement C (Data set A has a larger standard deviation than Data set B) is true.
  • Statement D (Data set A has the same mean as Data set B) is false.

Therefore, the two true statements are:

  • B. Data set A has a larger mean than data set B.
  • C. Data set A has a larger standard deviation than Data set B.