This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: ISEG – ISM BUSINESS RESEARCH METHODS Final Assignment EXERCISE 1 : Data : μ = 37 σ = 4 n = 25 σ x = n σ = 25 4 = 0.8 So: n σ μ) x ( z = 0.8 37) (38.2 = 1.5 Referring to the Z table Z (1.5) = 0.4332 So: 0.5  0.4332 = 0.0668 corresponding to 6.68% Conclusion : There is 6.68% that the average age of group is greater than 38.2 years old. As 6.68% is very low, we can’t assume that the engineers in this group are g enerally much older than the average. EXERCISE 2 : Data : n = 50 x = 196.02 (data from excel) s = 617.28(data from excel) 90% σ x = n s = 50 617.28 = 87.3097 So : n s z x 196.02 1.65 (87.3097) 196.02 + 144.0610 = $ 340.10 196.02  144.0610 = $ 51.96 Conclusion : The 90% confidence interval of the population mean for the incomes of western Pennsylvania credit union is between $ 340.10 and $ 51.96. EXERCISE 3 : Data : n = 8 (<30) x = 58.875 (data from excel) s = 5.083 (data from excel) d.f = n1 = 7 σ x = n s = 8 5.083 = 1.796 So : n s t x 58.875 1.8946 (1.796) 58.875 + 3.4027 = 62.28 ≃ 62 salaries 58.875  3.4027 = 55.47 ≃ 55 salaries Conclusion : The 90% confidence interval of the mean for the salaries of substitute teachers in this region is between 62 and 55 salaries....
View
Full
Document
This note was uploaded on 02/14/2010 for the course BR Business R taught by Professor Bob during the Spring '10 term at École Normale Supérieure.
 Spring '10
 Bob

Click to edit the document details