Question

in the city of Las Vegas, the researchers found the interval estimate to be too wide. What two changes can be made by the researchers in a future study in order to make the interval narrower? 6. (15 points) A study is planning to estimate the proportion of businesses started in the year 2006 that had failed within 10 years of their startup. What is the minimum sample size needed for estimating the correct proportion within 3% and a confidence level of 95%? (Assume that there is no preliminary data.) For credit, you must show work.

Answer 1

margin of error (E) - 0-03 Confidence interval =95% n? For there is no preliminary data Let take P=₂ margin of error error for the population proportion Zah P(1-P) n with the critical Z Z score Score assosciated is i ,96 can 95% confidence interval the left tail area be calculated by using 95% dal 95 -0.05 dy 100 غم ) d = 0.08 20.025 Z=1, 96 Z=1,96 lies in -da 0-975 left tail area 11 with the Z row starting z- table of C8,9Scanned with and Cams anher the column value of 0.06

1,96 ed! =11.96 E- tow P(1-P) 7th P(1-P) m ab1 ()(---) 0.03 - 1067:11 Sample nr 1068 CS sizenned with CamScanner