Question

A survey of n = 100 students from a large university revealed that 40 had some fear of the dentist. At the confidence level α = 0.94, the margin of error in your estimate of the proportion who have a fear of dentists is:

A: 0.101

B: 0.113

C: 0.086

D: 0.092

E: 0.081

Answer 1

Solution :

Given that,

n = 100

x = 40

Point estimate = sample proportion = = x / n = 40/100=0.4

1 -   = 1-0.4 =0.6

At 94% confidence level the z is ,

Z/2 = Z0.03 = 1.88   ( Using z table )

Margin of error = E = Z/2   * ((( * (1 - )) / n)

= 1.88 (((0.4*0.6) /100 )

E = 0.092