Business Statistics

302 Business Statistics

Solution For this question,

28

0.14

200

= =p

;

(1 0.14) 0.86= − =q

; n = 200

The required 90% condence interval is

2 2

p q p q

p z p p

z

n n

α α

× ×

− ≤ ≤

+

(0.14) (0.86) (0.14) (0.86)

0.14 (1.645) 0.14 (

1.645)

200 200

p

× ×

− ≤ ≤ +

0.0996  p  0.0

So, the company ofcers can estimate with 90% condence that population

proportion is in between 9.96% to 18.03%. Figure 9.25 is the Minitab output ex-

hibiting the construction of 95% condence interval for Example 9.14.

Statistical inference is the branch of statistics that deals with uncer-

tainty in decision making and provides a basis for making scientic

decisions. Statistical inference ...