1. Using the Normal Distribution
Nulake 6th form maths 1999 page 305

2. Using the Normal Distribution tables calculate the area under the standard normal curve for each of the following =
P(Z < -0.58)
P(-2.31 < Z < -1.67)
P(Z > )
P(-1.5 < Z < 1.5)
P(Z > )
P(-1.97 < Z < 0.425) = = = = =

3. The mean mark in a university stage one math exam was 51% with a standard deviation of 16%. Assuming the marks are normally distributed find the probability that a student selected at random scored
Less than 55%
If 250 students sat the math exam how many scored between 35 and 45%?
To standardise we use Z =
To find P(X < 55)
standardising = P(Z < )
Simplifying = P(Z < 0.25)
Using tables = =

4. The mean mark in a university stage one math exam was 51% with a standard deviation of 16%. Assuming the marks are normally distributed find the probability that a student selected at random scored
If 250 students sat the math exam how many scored between 35 and 45%?
To find P(35 < X < 45)
standardising = P( < Z < )
Simplifying = P(-1 < Z < )
Using tables = =
Number of students = x 250
= 48 students (rounding down)
-51
-51
-1 0
-0.375