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 4, 5, 7, 9, 10,

1 answer

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

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

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

  2. Calculate the variance: \[ \text{Variance} = \frac{(4 - 8)^2 + (5 - 8)^2 + (6 - 8)^2 + (12 - 8)^2 + (13 - 8)^2}{5} \] \[ = \frac{(-4)^2 + (-3)^2 + (-2)^2 + (4)^2 + (5)^2}{5} \] \[ = \frac{16 + 9 + 4 + 16 + 25}{5} = \frac{70}{5} = 14 \]

  3. Calculate the standard deviation (SD): \[ \text{SD} = \sqrt{14} \approx 3.74 \]

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

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

  2. Calculate the variance: \[ \text{Variance} = \frac{(4 - 7)^2 + (5 - 7)^2 + (7 - 7)^2 + (9 - 7)^2 + (10 - 7)^2}{5} \] \[ = \frac{(-3)^2 + (-2)^2 + (0)^2 + (2)^2 + (3)^2}{5} \] \[ = \frac{9 + 4 + 0 + 4 + 9}{5} = \frac{26}{5} = 5.2 \]

  3. Calculate the standard deviation (SD): \[ \text{SD} = \sqrt{5.2} \approx 2.28 \]

Conclusion

  • Standard Deviation of Data Set A: Approximately 3.74
  • Standard Deviation of Data Set B: Approximately 2.28

Rounding to the nearest hundredths:

  • SD of Data Set A: 3.74
  • SD of Data Set B: 2.28

Variability Comparison

Data Set A has a higher standard deviation of 3.74, indicating greater variability in the data compared to Data Set B, which has a standard deviation of 2.28.