**Class 23: Confidence Intervals**

**Discussion 1**

Read
the article ÒMany in U.S. Want Texting at the Wheel to Be IllegalÓ from the New
York Times.

1)
The article says that 50% of the people polled
said that the punishment for texting while driving should be as severe as for
drunken driving. What do *you* think?

2)
Attach a standard error to this estimate of 50%. Also calculate two times the standard
error.

3)
At the end of the article, it says that the poll
has a Òmargin of sampling error of plus or minus 3 percentage points. How does 3 percentage points compare to
the standard error you calculated?
How does it compare to twice the standard error?

4) This is how the New York Times explains the
Òmargin of errorÓ of 3 percentage points, in the side article ÒHow the Poll was
ConductedÓ:

ÒIn theory, in 19 cases out
of 20, overall results based on such samples will differ by no more than 3 percentage
points in either direction from what would have been obtained by seeking to
interview all American adults.Ó

What is
19/20 as a percent? What do you think the New York Times
means?

**Discussion 2**