and . Given , the value of is:

Answer and explanation

Correct answer: C. 8

  1. Step 1: gives , so the -score of 62 is 1.5.
  2. Step 2: , so .
Answer
8.
Why not the others: 12 is the distance from the mean in marks, not standard deviations; 18 multiplies instead of dividing; 4 has no basis in the -score equation.

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X sim N(50, sigma 2) and Pr(X > 62)… | Victorian VCE