Portfolio task

...

s x =7.50x = 7.508347248 s x = 12x =13.73485669[pic 24][pic 25][pic 26][pic 27]

Z value calculation:

Z= = = -60.01533144 [pic 28][pic 29]

Conclusion: Z test Z critical. Reject H0 [-60.0153 fail in reject region]. At the 5% level there is evidence of significant decrease of cost between the two periods.[pic 30]

B) Current sample n 1 previous sample n 2

N 450 300

R (already tried) 35 42

P (proportion) 0.07 0.14

Pooled proportion: 0.1026

H 0: P current = P previous = π H 1: P current previous[pic 31]

H 0: There is no difference between the current and previous proportions

H1: There is a difference between the proportions

A = 0.05 z critical = (2 tailed test) [pic 32]

= = 0.1026 Pooled estimate proportion calculation[pic 33][pic 34]

Z= = -3.095049361 Z test calculation[pic 35]

Conclusion: Z test Z test critical Reject H0. [-3.095049361 lie into reject region] At 5 % level there is evidence of difference of proportion of slow-moving stock. [pic 36]

Task 3:

N= 6 = 473.83 s=7.414 = 0.05/2 =490[pic 37][pic 38][pic 39]

Z test Value calculation:

Z = = =-5, 342358935[pic 40][pic 41]

Degree of freedom (df) = n-1 = 5 Critical t value (with n-1 df) from table = [pic 42]

H0: = 490 The mean units per box is 490 H1: µ 490 The mean units per box isn’t 490[pic 43][pic 44]

Conclusion: Test statistic critical value [-5.342358935 fail in reject region] Reject Ho. At 5% of level of evidence the evidence suggest that average content isn’t 490 units per box.[pic 45]