Step 1:
\The standard deviation of selling prices for used two-year old Corvettes σ is $ 2517.
\98 % confidence interval of sample mean is within $ 250.
\Here margin of error E is 250.
\Z for 98 % confidence interval is 2.33.
\Margin of error : ![\"image\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=7b0fc7ca65810328bed2141e605dd116.png\")
,
where Z is the Z-score for 90 % of confidence interval.
\σ is the standard deviation
\n is sample size.
\Step 2:
\Find the population mean .
\![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=348fc0d892b5ae9a9cd6a7ca50810171.png\")
Sample size of the selling prices for used two-year old Corvettes is 550.
\Solution:
\Sample size of the selling prices for used two-year old Corvettes is 550.
\