Lisa watches the vehicles that passes buy in front of he apartment building. she has counted 15 vans and 30 cars. what is the approximate probability that the next vehicle lisa sees is a van?
A) 25%
B) 0.5
C)1/3
D3/2

As a manufacturer of golf equipment, the spalding corporation wants to estimate the proportion of golfers who are left-handed. how many golfers must be surveyed if we want 99% confidence that the sample proportion has a margin of error of 0.025? assume that a previous study suggests that 20% of golfers are left-handed.