"Productivity" is a term you hear quite often in news reports
about the economy. Productivity isnt everything, but in the long
run it is almost everything. A countrys ability to improve its
standard of living over time depends almost entirely on its ability
to raise its output per worker.
Productivity measures how efficiently production inputs, such as
labor and capital, are being used in an economy to produce a given
level of output. Knowledgeable, skilled workers with the proper
tools such as computers or manufacturing equipment result in high
productivity.
This Productivity Excel file shows the percent change
in worker output per hour from the previous quarter for the United
States from 1988 through 2008.
Question 1. Make a histogram of the
productivity data in the above file. Select the histogram below
that is closest in shape to the histogram of the productivity
data.
Question 2. These data can be approximated
quite well by a N(3.4, 3.1) model. Economists become alarmed when
productivity decreases. According to the normal model what is the
probability that the percent change in worker output per hour from
the previous quarter is more than 1.7 standard deviations
below the mean?
Question 3. What is the probability that the
percent change in worker output from the previous quarter is
between -1.25 and 8.05? Use the normal model
mentioned at the beginning of question 2.