Statistics and Probability Reviewer

What random variable is illustrated if the experiment requires getting the sum of the spots on two dice wherein the number of possible outcomes is finite?

• Binomial Random Variable

• Continuous Random Variable

• Discrete Random Variable

• Infinite Random Variable

What random variable is illustrated if the experiment attempts to list possibilities, say for example the time that the first call of the day is received at a local police station.

• Binomial Random Variable

• Continuous Random Variable

• Discrete Random Variable

• Infinite Random Variable

An investor has 5 stocks that she follows each day. The random variable being studied is X, the number of stocks that increase in value each day: X 0 1 2 3 4 5 PX=x ? 0.30 0.20 0.10 0.05 0.01 What is the probability that no stock will increase in value?

• 0.034

• 0.16

• 0.34

• 0.66

In a family with 3 children, what is the probability of having 1 boy and 2 girls assuming equal probabilities for boys and girls?

• 18

• 14

• 12

• 38

Which one of these variables is a continuous random variable?

• The number of tattoos on a randomly selected person has.

• The number of correct guesses on a multiple choice test.

• The time it takes a randomly selected student to complete an exam.

• The number of women taller than 68 inches in a random sample of 5 women.

Which one of these 'X' variable is a discrete random variable?

• A UPS package is randomly selected and X is the weight in pounds of the package.

• A student is randomly selected and X is the number of correct answers on a two question multiple-choice quiz.

• An experiment in chemistry is repeated many times and X is the time required for a reaction to occur in seconds.

• A student is randomly selected and X is the distance they must travel in feet to go from their dorm room door to the door of their first class on Monday morning.

Let the random variable X represent the profit made on a randomly selected day by a certain store. Assume that X is approximately normal with mean of Php. 360 and standard deviation of Php.50. What is PX>Php.400?

• 0.2119

• 0.2881

• 0.5319

• 0.7881

if you have14 probability of gaining Php. 12 000 and 34 probability of gaining Php. 5 000, what is your expected gain?

• Php. 6 750

• Php. 7 650

• Php. 8 250

• Php. 9 350

If the town of Villasis, the number of cell phones in a household is a random variable W with the following distribution: W 0 1 2 3 4 5 P(W) 0.1 0.1 0.25 0.3 0.2 0.05 What is the probability that randomly-selected household has at least two cell phones is:

• 0.20

• 0.25

• 0.70

• 0.80

A random variable X has a probability distribution as follows: X 0 1 2 3 P(X) 2k 3k 13k 2k Where k is a positive constant, the probability P(X<2.0) is equal to:

• 0.15

• 0.25

• 0.65

• 0.90