(a)[3]
Find the mean and variance of the amount people pay for using the video game.
(b)[3]
Each day, $35$ people use the video game independently. Find the mean and variance of the total amount paid by the $35$ people.
Mathematics 9709 · AS & A Level · Linear combinations of random variables
Linear combinations of random variables — practice question
At an entertainment centre, the charge for playing a particular video game is $\$0.40$ for each minute. The number of minutes that people spend on the video game has mean $15$ and variance $9$.