Normal Probability

The mean temperature in Glens Falls for the month of February is 23 degrees with a standard deviation of 4.2 degrees.  Approximately what percent of days in February will have days below 23 degrees?

• 5%

• 34%

• 50%

• 68%

The table represents the probability of guessing correct on a 5 question true-false quiz. Find the mean and the standard deviation.

• μ = .4; σ = 7.5

• μ = 2.5; σ = 1.1

• μ = 3; σ = 1.3

• μ = .1; σ = 0

The American Red Cross says that about 11% of the U.S. population has Type B blood. A blood drive is being held at your school. What is the probability that at least 2 of the first 10 blood donors has Type B blood? 

• 0.088

• 0.697

• 0.214

• 0.303 

A marketing survey compiled data on the number of cars in households.  If X = the number of cars in a randomly selected household, and we omit the rare cases of more than 5 cars, then X has the following probability distribution: 
X           0          1          2          3           4           5    
P(X)   0.24    0.37    0.20    0.11    0.05     0.03
What is the probability that a randomly chosen household has at least two cars?

• 0.20

• 0.29

• 0.39

• 0.61

• Uniform

• Skewed Left

• Bimodal

• Approximately Normal

• 39.8

• 31.2

• 8.6

• 10

• 11.77

• 138.5

• 16

• 5

The chance of flipping a tail on a normal coin is equally as likely as flipping a head.

• True

• False

If you want to choose a Red marble from a bag of 10 Red marbles, your probability is....

• 0

• 1/10

• 1

• 5/10

If you draw one card from a standard deck, what is the probability of drawing a 5 or a diamond?

• 1/26

• 1/13

• 4/13

• 17/52