Question

The minimum and maximum observations in a population are 26 and 66, respectively. What is the minimum sample size n required to estimate u with 95% confidence if the desired margin of error is E= 3.4? What happens to n if you decide to estimate u with 90% confidence? (You may find it useful to reference the z table. Round intermediate calculations to at least 4 decimal places and "z" value to 3 decimal places. Round up your answers to the nearest whole number.) Confidence Level 95% 90%

Answer 1

a) Given || Using range rule of thumbo || | 668 N 3.4 Range/4 10 0.05 -1.959963985 1.96 | Critical z | || Minimum sample size = IV IV (1.96*10/3.4) IV 33.23183391 Required sample sizen L Using excel =(normsinva/2)*10/3.4)^2 = 33.23061264 34

b) Given | 3.4 Range/4 Using range rule of thumb | 10 668 N | Critical z || 0.1 -1.644853627 1.645 || Minimum sample size = TV (1.645*10/3.4) IVIV 23.40852076 Required sample sizen 24 L Using excel =(normsinv(a/2)*10/3.4)^2 = 23.40435514 24