Concept explainers
The 20th percentile of standard normal variable.
Answer to Problem 2.4CYU
The 20th percentile of standard normal variable is -0.84.
Explanation of Solution
Proportion of observations from a standard
The area under standard normal curve is drawn using Desmos software and shaded. The area under normal curve is the shaded region to the left of -0.84 in the graph.
The corresponding probability is read using table A. The observation corresponding row heading -0.8 (under column z) and column heading .04 is the area under normal curve with reading 0.2004.
Conclusion: Proportion of observations that fall under the standard normal region z <-0.84 is 20.04%. Hence 20th percentile is -0.84
Chapter 2 Solutions
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