Use the standard deviation to compare the variability of the data sets round to the nearest hundredths data set a 4, 5, 6, 12, 13 data set b for, 5, 7, 9, 10,

1 answer

To compare the variability of the two data sets using the standard deviation, we will calculate the standard deviation for each data set.

Data Set A: 4, 5, 6, 12, 13

  1. Calculate the Mean (Average): \[ \text{Mean}_A = \frac{4 + 5 + 6 + 12 + 13}{5} = \frac{40}{5} = 8 \]

  2. Calculate Each Deviation from the Mean:

    • \(4 - 8 = -4\)
    • \(5 - 8 = -3\)
    • \(6 - 8 = -2\)
    • \(12 - 8 = 4\)
    • \(13 - 8 = 5\)
  3. Square Each Deviation:

    • \((-4)^2 = 16\)
    • \((-3)^2 = 9\)
    • \((-2)^2 = 4\)
    • \(4^2 = 16\)
    • \(5^2 = 25\)
  4. Calculate the Variance: \[ \text{Variance}_A = \frac{16 + 9 + 4 + 16 + 25}{5} = \frac{70}{5} = 14 \]

  5. Calculate the Standard Deviation: \[ \text{Standard Deviation}_A = \sqrt{14} \approx 3.74 \]

Data Set B: 4, 5, 7, 9, 10

  1. Calculate the Mean (Average): \[ \text{Mean}_B = \frac{4 + 5 + 7 + 9 + 10}{5} = \frac{35}{5} = 7 \]

  2. Calculate Each Deviation from the Mean:

    • \(4 - 7 = -3\)
    • \(5 - 7 = -2\)
    • \(7 - 7 = 0\)
    • \(9 - 7 = 2\)
    • \(10 - 7 = 3\)
  3. Square Each Deviation:

    • \((-3)^2 = 9\)
    • \((-2)^2 = 4\)
    • \(0^2 = 0\)
    • \(2^2 = 4\)
    • \(3^2 = 9\)
  4. Calculate the Variance: \[ \text{Variance}_B = \frac{9 + 4 + 0 + 4 + 9}{5} = \frac{26}{5} = 5.2 \]

  5. Calculate the Standard Deviation: \[ \text{Standard Deviation}_B = \sqrt{5.2} \approx 2.28 \]

Summary of Results:

  • Standard Deviation of Data Set A: \(\approx 3.74\)
  • Standard Deviation of Data Set B: \(\approx 2.28\)

Conclusion:

The standard deviation of Data Set A (approximately 3.74) is greater than the standard deviation of Data Set B (approximately 2.28), indicating that Data Set A has greater variability compared to Data Set B.