Respuesta :

mhanifa

Answer:

  • P(x < 84) = 0.3085 or approximately 31%

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Hello to you from Brainly team!

Given

  • Mean grade μ = 86,
  • Standard deviation σ = 4,
  • Grade limit x = 84.

To find

  • Probability of that a randomly selected grade is less than 84 or P(x < 84).

Solution

Find z-score using relevant equation:

  • z = (x - μ)/σ

Substitute values and calculate:

  • z = (84 - 86)/4 = - 0.5

Using the z-score table find the corresponding P- value.

  • P(x < 84) = 0.30854 or approximately 31%