Question

if mean is 60, standard deviation is 12, N is 400
find the number of cases above 70
find the number of cases below 75
find the number of cases between 50 and 60
find the number of cases failed if passing Mark's are 30
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Answer 1

Answer:

nahi pta meko yrr kaise batau

Answer 2

6.2 Using the Normal Distributions

The blue shaded area in the following graph indicates the area to the left of x.

P(X < a) = Area to the left of the vertical line through a. (blue area)

P(X > a) = Area to the right of the vertical line through a. (white area)

P(X > a) is also equal to 1 – P(X < a).

Remember,

P(X < a) = P(X ≤ a) and P(X > a) = P(X ≥ a) for continuous distributions.