Answer :

mhanifa

Answer:

  • 3.0

Step-by-step explanation:

Sample standard deviation is found by steps below.

Find the mean:

  • μ = (9 + 15 + 13 + 9 + 15)/5 = 12.2

Find deviations from the mean and their squares:

  • 9 - 12.2 = - 3.2 ⇒ (-3.2)² = 10.24
  • 15 - 12.2 = 2.8 ⇒ 2.8² = 7.84
  • 13 - 12.2 = 0.8 ⇒ 0.8² = 0.64
  • 9 - 12.2 = - 3.2 ⇒ (-3.2)² = 10.24
  • 15 - 12.2 = 2.8 ⇒ 2.8² = 7.84

Sum the squares:

  • 10.24*2 + 7.84*2 + 0.64 = 36.8

Divide by N - 1 (N - number of samples):

  • 36.8/(5 - 1) = 9.2

Square root is the sample standard deviation:

  • σ = √9.2 = 3.0 (rounded)

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