Exercises: Develop an Empirical Probability Distribution and Find Its Expected Value
Work through each section in order. To turn a frequency table into a probability distribution, estimate each probability as a RELATIVE FREQUENCY: count divided by total (or percent divided by 100). Every probability must be between 0 and 1, and they should sum to about 1. Compute the expected value as $E(X) = \sum x \cdot P(X = x)$, and scale to a population total with $n \cdot E(X)$. State any modeling choice you make for an open-ended category. Round as directed.
Fluency Practice
Build distributions, check the sum, and compute expected values.
A distribution for the number of TVs per household has an open-ended top category "4 or more" with probability 0.12. To compute , the class decides to treat "4 or more" as the representative value 4. Using that decision, what is the contribution of the "4 or more" category to (that is, the value times its probability)?