Xr12-128 An advertising company was awarded the contract to design advertising for Rolls Royce automobiles.

An executive in the firm decided to pitch the product not only to the affluent in the United States but also to those who think they are in the top 1% of income earners in the country. A survey was undertaken that, among other questions, asked respondents 25 and older where their annual income ranked. The following responses were given.

1  Top 1%

2  Top 5% but not top 1%

3  Top 10% but not top 5%

4  Top 25% but not top 10%

5  Bottom 75%

Estimate with 90% confidence the number of Americans 25 and older who believe they are in the top 1% of income earners. The number of Americans 25 and older is 231 million (Statistical Abstract of the United States, 2009, Table 18).