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11 grade maths others

The variance of the data 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 is :

  • A. 15
  • B. 20
  • C. 30
  • D. 33

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9 Months agoGrade
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1 Answer

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ApprovedApproved Tutor Answer9 Months ago

To find the variance of the given data set (6, 8, 10, 12, 14, 16, 18, 20, 22, 24), follow these steps:

Step 1: Calculate the Mean

The mean (average) is calculated by adding all the numbers together and dividing by the total count.

  • Sum = 6 + 8 + 10 + 12 + 14 + 16 + 18 + 20 + 22 + 24 = 180
  • Count = 10
  • Mean = 180 / 10 = 18

Step 2: Find the Squared Differences

Next, subtract the mean from each number and square the result:

  • (6 - 18)² = 144
  • (8 - 18)² = 100
  • (10 - 18)² = 64
  • (12 - 18)² = 36
  • (14 - 18)² = 16
  • (16 - 18)² = 4
  • (18 - 18)² = 0
  • (20 - 18)² = 4
  • (22 - 18)² = 16
  • (24 - 18)² = 36

Step 3: Calculate the Variance

Add all the squared differences together and divide by the number of data points:

  • Sum of squared differences = 144 + 100 + 64 + 36 + 16 + 4 + 0 + 4 + 16 + 36 = 420
  • Variance = 420 / 10 = 42

Final Answer

The variance of the data set is 42. Since this value is not listed among the options (A. 15, B. 20, C. 30, D. 33), it appears there may be an error in the provided choices.