Question

Complete the following sentences by selecting the correct answer from the drop-down. Answers have been rounded to the nearest hundredths.

Use the standard deviation to compare the variability of the datasets.

Dataset A: 4, 5, 6, 12, 13

Dataset B: 4, 5, 7, 9, 10

(1 point)
The standard deviation of Dataset A is
. The standard deviation of a Dataset B is
. The standard deviation of
is larger than that of
, so
has more variability.
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1 answer

To compare the variability of the datasets, we need to calculate the standard deviation for each dataset.

Dataset A: 4, 5, 6, 12, 13

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

  2. Calculate each deviation from the mean, square it, and find the average of these squared deviations: \[ (4 - 8)^2 = (-4)^2 = 16 \] \[ (5 - 8)^2 = (-3)^2 = 9 \] \[ (6 - 8)^2 = (-2)^2 = 4 \] \[ (12 - 8)^2 = (4)^2 = 16 \] \[ (13 - 8)^2 = (5)^2 = 25 \]

    Now we sum these squares: \[ 16 + 9 + 4 + 16 + 25 = 70 \]

    The variance (population variance formula) is: \[ \text{Variance} = \frac{70}{5} = 14 \]

    Therefore, the standard deviation is: \[ \text{Standard Deviation} = \sqrt{14} \approx 3.74 \]

Dataset B: 4, 5, 7, 9, 10

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

  2. Calculate each deviation from the mean, square it, and find the average of these squared deviations: \[ (4 - 7)^2 = (-3)^2 = 9 \] \[ (5 - 7)^2 = (-2)^2 = 4 \] \[ (7 - 7)^2 = (0)^2 = 0 \] \[ (9 - 7)^2 = (2)^2 = 4 \] \[ (10 - 7)^2 = (3)^2 = 9 \]

    Now we sum these squares: \[ 9 + 4 + 0 + 4 + 9 = 26 \]

    The variance (population variance formula) is: \[ \text{Variance} = \frac{26}{5} = 5.2 \]

    Therefore, the standard deviation is: \[ \text{Standard Deviation} = \sqrt{5.2} \approx 2.28 \]

Now to complete the sentences:

The standard deviation of Dataset A is 3.74. The standard deviation of Dataset B is 2.28. The standard deviation of Dataset A is larger than that of Dataset B, so Dataset A has more variability.