Did Sales Increase? Funny MOEs from the Federal Gov’t


Sales of new single-family houses in September 2017 were at a seasonally adjusted annual rate of 667,000, according to estimates released jointly today by the U.S. Census Bureau and the Department of Housing and Urban Development. This is 18.9 percent (±19.0 percent)* above the revised August rate of 561,000 and is 17.0 percent (±22.4 percent)* above the September 2016 estimate of 570,000.


Chance or Not?

A Poll of the US population ask respondents how they feel about the honesty and ethical standards of people in different fields.  The percentage of Americans who rate clergy “high or very high” in terms of ethical standards dropped from 60% in 2010 to 54% in 2015.

This change may have been due to cultural shifts in the reception of clergy, or it may be due to chance variation.

In each year the poll uses an independent simple random sample of a thousand Americans.

  1. Would you do a one sample or a two sample hypothesis test?  Why?
  2. Formulate a null and alternative hypothesis.
  3. If you wanted to make a box model to answer this question would you use one or two boxes? Why?  How many tickets would you put into each box? How many draws from each box?  What would you write on the tickets?
  4. Is the difference between the perception of clergy in 2010 and 2015 due to random chance.