Random variable also known as stochastic variables are variables that are used in statistics and probability, The value of a random variable must be determined by chance which remain uncertain and depends on the outcome of a random process or experiment.
Unlike algebra, when random variable is introduced into a mathematical model, it is represented by capital letter and it has a single numerical value.
The driver's tip was $1.45 because the trip cost $8.55 (2.25+1.5+1.5+1.5+1.5+ 0.3) and Eric gave the driver $10 so to find how much the driver got tipped, you need to subtract 8.55 from 10 so $10 - $ 8.55 = $1.45
