Question 1

The mayor of Beltsville has commissioned a research company to estimate the average age of the houses in a large historical district in the town.Data on 120 randomly selected properties are collected,and a histogram of the sample data shows a right-skewed distribution with several large outliers.The person leading this project decides that the standard t procedures should not be used.He decides to use the 25% trimmed mean as a measure of center.The leader of the project then decides to bootstrap the 25% trimmed mean.The bootstrap distribution is shown below.Some summary measures are given as well.  Number of Replications: 500
Summary Statistics:
Observed Mean Bias SE
TrimMean 53.675 53.05 4.67
Percentiles:
2.5% 5% 25% 50% 75% 95% 97.5%
TrimMean 41.05 44.28 50.45 53.20 56.05 60.80 63.82
The dashed line in the histogram represents the mean of the resamples.The solid line represents the observed value of the trimmed mean in the original sample.
As part of the summary measure,the value 4.67 is reported as the SE.How was this value calculated,and what does it represent?

Accepted Answer

The answer of The mayor of Beltsville has commissioned a...

Question 2

A real estate agency with property all throughout the Midwest is interested in home prices within the state of Michigan.The average price of a simple random sample of residential properties in the Upper Peninsula is compared to the average price of a simple random sample of residential properties in the Lower Peninsula.From the collected data,2440 resamples without replacement are taken.The distribution of the difference in means based on the resamples is shown below (in thousands of dollars).  The observed difference in sample mean prices is $300,000.What is the estimate of the P-value?
A)3/2440
B)3/2439
C)4/2440
D)4/2441

Accepted Answer

The answer of A real estate agency with property all...

Quiz 16: Bootstrap Methods and Permutation Tests