Question

Use the table of standard normal probabilities (z table) to answer the following questions. Please explain...

Use the table of standard normal probabilities (z table) to answer the following questions. Please explain how you calculate.

  1. What is P(z >2.5)?
  2. What is P(-0.8 < z < 1.5)?
  3. What is P(0.65< z < 1.36)?  
  4. What z-value leaves 80 % of the normal distribution to its right?
  5. What z-value, and its negative, leaves 10 % of the normal distribution in each tail (a total of 20% of the distribution in both tails combined)?

Homework Answers

Answer #1

stands for cumulative standard normal distribution.

a) The probability,

(Look up the standard normal table for z=-2.5)

b) The probability,

c) The probability,

d) We need to find the 20-th percentile of standard normal distribution.

e) We need to find the 90-th percentile of standard normal distribution.

The required z-value is

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