Exercises on The Standard Normal Curve

1. Which of the following is NOT a characteristic of the Standard Normal Curve?

  The area under the curve is 1.
  The curve is symmetric about the mean.
  The mean is 0.
  The standard deviation is 0.

2. Find the area under the standard normal curve between z = 0 and z = 1.45.

  The area is 0.4265.
  The area is 0.1736.
  The area is 0.4394.
  The area is 0.4349.

3. Find the area under the standard normal curve between z = 0 and z = -2.65.

  The area is -0.4960.
  The area is 0.4959.
  The area is 0.4948.
  The area is 0.4960.

4. Find the area under the standard normal curve between z = -1.00 and z = 1.00.

  The area is 0.3413.
  The area is 0.6826.
  The area is 0.1587.
  The area is 0.5000.

5. Find the area under the standard normal curve between z = -0.58 and z = 1.23.

  The area is 0.1093.
  The area is 0.1717.
  The area is 0.6097.
  The area is 0.2810.

6. Find the probability that z > 0.

  P(z > 0) = 0.5000
  P(z > 0) = 0.0000.
  P(z > 0) = 1.0000
  P(z > 0) = 0.4999

7. Find the probability that z > 2.00.

  P(z > 2.00) = 0.9772.
  P(z > 2.00) = 0.0228.
  P(z > 2.00) = 0.4772.
  P(z > 2.00) = 0.5287.

8. Find the probability that z > 2.00 or less than -2.00.

  The probability is 0.0456.
  The probability is 0.9772.
  The probability is 0.2280.
  The probability is 0.4772.

9. Find P(1.99 < z < 2.19).

  P(1.99 < z < 2.19) = 0.0358.
  P(1.99 < z < 2.19) = 0.9910.
  P(1.99 < z < 2.19) = 0.9624.
  P(1.99 < z < 2.19) = 0.0090.

10. What is the value of z that separates the lower 10% of the curve from the upper 90% of the curve?

  z = -0.25.
  z = 0.25.
  z = 1.28.
  z = -1.28.

11. What is the value of z that separates the upper 95% of the curve from the lower 5% of the curve?

  z = 0.950
  z = 1.645.
  z = 1.65.
  z = -1.645.

12. What is the value of z that separates the lower 99% of the curve from the upper 1% of the curve?

  z = 2.575.
  z = 2.33.
  z = -2.575.
  z = -2.33.