Answer Key: Assignment 5

6.11 (15 points)

Histogram of Sample Mean with Size=25

Descriptive Statistics

Variable N Mean Median TrMean StDev SE Mean

C22 500 25.481 25.400 25.482 3.201 0.143

Variable Minimum Maximum Q1 Q3

C22 14.800 36.150 23.450 27.450

Sample Median Histogram with Size=25

Descriptive Statistics

Variable N Mean Median TrMean StDev SE Mean

C23 500 25.511 25.000 25.539 5.091 0.228

Variable Minimum Maximum Q1 Q3

C23 9.500 39.000 22.000 29.000

A) Yes.

B) The median distribution displays greater variation. StDev for sampling median distribution is 5.091 and StdDev for sampling mean distribution is 3.201.

6.27 (15 points)

A) According to the CLT, we will use Normal Distribution to approximate the distribution of sample mean.

=89.34

===1.308294

B) The sampling distribution should be like a Normal(89.34,1.308294)

C) P(>88)=1-P(<=88)=1-0.1529=0.8471

P(<87)=0.0368

Case Book Question (15 points)

Refer to the answer of question 6.11 and workshop notes.