STAT&PROB NAT

It is a variable being measured to produce numerical observations associated with the random outcomes of a chance experiment.

• fixed variable

• dependent variable

• independent variable

• random variable

Which of the following is a discrete random variable?

• the number of patients in a hospital

• the average weight of female athletes

• the average amount of electricity consumed

• the amount of paint used in repainting a building

What are the possible outcomes of a random variable when a coin is tossed once?

• Tail (T) and Head (H)

• The number of dots 1,2,3,4,5,6

• Tail and Tail (TT), and Head and Head (HH)

• The pair of even number of dots (2,2),(2,4),(2,6),(4,2),(4,4),(4,6),(6,2),(6,4) and (6,6)

Which is NOT a discrete probability distribution?

• 
• 
• 
• 

A fair coin is tossed three times and the sequence of heads (H) and tails (T) is observed. What is the probability that no heads will appear?

• 1/8

• 3/8

• 5/8

• 2/3

The expected value of a random variable is the ___________________,

• largest value that will ever occur.

• mean value over an infinite number of observations of the variable.

• most common value over an infinite number of observations of the variable.

• value that has the highest probability of occurring.

Cardo sells a maximum of 3 tickets per customer. Let T be the number of tickets sold to a random customer. Below is the probability distribution of T.

• 0.16

• 0.17

• 0.18

• 0.19

What is the mean of the probability distribution?

• 1.64

• 1.65

• 1.66

• 1.67

Which statement is NOT true about the variance of a discrete random variable?

• Variance is always nonnegative.

• It tells the average of the items in a discrete probability distribution

• It measures how far apart the elements of the set are spread out

• High variance indicates that the data points are very spread out around the mean.

Which of the following is NOT a property of a normal curve?

• The total area under it is 1.

• The curve is symmetric about the center.

• It is divided into positive 2 and negative 2 standard deviations

• The mean, median, and mode have the same value and are located at the same point.