In: Math
In 2011, when the Gallup organization polled investors, 34%
rated gold the best long-term investment. In...
In 2011, when the Gallup organization polled investors, 34%
rated gold the best long-term investment. In April of 2013 Gallup
surveyed a random sample of U.S. adults. Respondents were asked to
select the best long-term investment from a list of possibilities.
Only 241 of the 1005 respondents chose gold as the best long-term
investment. By contrast, only 91 chose bonds.
- Compute the standard error for each sample proportion. Compute
and describe a 95% confidence interval in the context of the
question.
- Do you think opinions about the value of gold as a long-term
investment have really changed from the old 34% favorability rate,
or do you think this is just sample variability? Explain.
- Suppose we want to increase the margin of error to 3%, what is
the necessary sample size?
- Based on the sample size obtained in part c, suppose 120
respondents chose gold as the best long-term investment. Compute
the standard error for choosing gold as the best long-term
investment. Compute and describe a 95% confidence interval in the
context of the question.
- Based on the results of part d, do you think opinions about the
value of gold as a long-term investment have really changed from
the old 34% favorability rate, or do you think this is just sample
variability? Explain.