Question

A new soft drink is being market tested. According to the result of a survey, 50% of consumers will like the new drink. A sample of 100 people tasted the new drink. The mean and standard deviation of the sample proportion of customers who will like the new drink are

A new soft drink is being market tested. According to the result of a survey,50% of consumers will like the new drink. A sample of 100 people tasted the new drink. What is the probability that more than 60% of customers from the sample will indicate they like the drink?

Answer 1

Solution

Given that,

p = 0.50

1 - p = 1 - 0.50 = 0.50

n = 100

= p = 0.50

=  [p( 1 - p ) / n] = [(0.50 * 0.50) / 100 ] = 0.05

P( > 0.60) = 1 - P( < 0.60 )

= 1 - P(( - ) / < (0.60 - 0.50) / 0.05)

= 1 - P(z < 2.00)

Using z table

= 1 - 0.9772

= 0.0228