Question

the proportion of the bills that is online are 27%. if you were to select 80 bills at random, what is the probability that at least 35% would be paid online?

Answer 1

Solution:

Given that,

n = 80

= 27% =0.27

1 - = 1 - 0.27 = 0.73

=   =0.27

= ( 1 - ) / n

=   0.27 * 0.73 / 80

= 0.0496

= 0.0496

P(   0.35 )

1 - P ( 0.35 )

1 -P ( -    / ) ( 0.35 - 0.27 / 0.0496 )

1 -P (z   0.08 / 0.0496 )

1 - P ( z 1.61 )

Using z table

= 1 - 0.9463

= 0.0537

Probability = 0.0537