Business Statistics - Ch. 6

The following table represents the number of cartons of milk that the children at Hoover-Wood Elementary school purchase for lunch. Number of Milk Cartons 0 1 2 3 or more Probability 0.2 0.7 - 0.02 The probability that a student purchases 2 milk cartons is

0.08

The sum of the probabilities of all x values in a discrete distribution equals

1

The CDF of a discrete random variable is a rule that defines

P(X ≤ x)

Which of the following are examples of discrete random variables?

The number of people who will vote for the democratic candidate in the next presidential election The number of students who received an "A" on their statistics exam

True or false: σ2 represents the variance.

True

Discrete random variables:

can have a finite or infinite number of values. are countable. have a set of distinct values.

The variance of a discrete random variable is the sum of the ________ from μ weighted by the individual ___________ for each x.

squared deviations; probabilities

The expected value of a discrete distribution is the

sum of the x values weighted by their probabilities.

Hotels R Us has kept the following records concerning the number of guests in a room. Number of guests 1 2 3 4 Probability 0.35 0.4 0.1 0.15 The expected number of guests in a room is

2.05