How many people can be expected to attend the spring festival?

Question

An outdoor spring festival is planned. The weatherman is predicting a 20% chance of rain, 30% chance of a cloudy day, and 50% chance of sunshine. The committee feels that if it rains, then only 500 people will attend, if it is cloudy, then only 10000 will attend, and if the sunny, then 15000 will attend. How many people can be expected to attend the spring festival?

Answer 1

To find expected value, you multiply the probability of each event by the value of each event, then add those all up. The conditions here are:

 

rain: 20% chance, 500 people show up

cloudy: 30% chance, 1000 people

sunny: 50% chance, 15,000 people

 

EV = 0.20*500 + 0.30*1000 + 0.50*15,000

 

Hope this helps, and if you have further questions, please comment.