Question

Find the mean, the mounan, and the standard deviation, rounded to one decimal. A sample of 45 employees was taken. 28 of them have used public transport for their commute, 21 have used a bike. 18 answered that they have used both public transit and a bike. How many employees have used neither public transport nor a bike?

Answer 1

Total number of employees in sample = 45

Number of employees using public transport, P = 28

Number of employees using bike, B = 21

Number of employees using both , P∩B = 18

We want to find number of employees neither using public transport nor bike, that is (PUB)' = 45 - PUB

PUB = P + B - P∩B

= 28 + 21 - 18

= 31

So, (PUB)' = 45 - 31

= 14

So, number of employees neither using public transport nor bike = 14