Statistics and Probability Quiz

Which of the following is NOT a characteristic of a normal distribution?

• It is bell-shaped.

• The mean, median, and mode are equal.

• The area under the normal curve is equal to 0.5 or 50%.

• It is denser in the center and less dense in the tails.

What are the two parameters that define a normal distribution?

• mean and median

• mean and standard deviation

• mode and variance

• nominal and categorical

As shown in the figure, what is the area under the standard normal curve between 0 and 1.88?

• 0.4693

• 0.4699

• 0.4726

• 0.4750

The length of a newborn alligator is normally distributed with mean μ=7 inches and standard deviation σ=2 inches. This can be represented by:

• 
• 
• 
• 

Determine the z value for a normal distribution with μ=16, σ=3, and x=12.

• -2.15

• -1.33

• 1.57

• 2.78

A coffee-vending machine is set to dispense amounts of coffee per cup that follows a normal distribution with a mean of 200 mL and a standard deviation of 10 mL. What is the probability that a randomly selected cup will contain more than 225 mL of coffee as dispensed by the machine?

• 0.0054

• 0.0062

• 0.5062

• 0.9938

The process of making inferences about the population based on the information obtained from a sample is called ____________.

• descriptive statistics

• evaluation

• estimation

• hypothesis testing

A single statistic whose realized value is used to estimate an unknown parameter is known as ____________.

• confidence interval estimator

• critical value estimator

• interval estimator

• point estimator

The realized value of the interval estimator is known as ____________.

• confidence interval estimate

• critical value estimate

• interval estimate

• point estimate

Which of the following is a property of a good estimator?

• It must be inconsistent.

• It must be a biased estimator.

• It must be a relatively inefficient estimator.

• The mean of the estimates obtained from the samples of a given size is equal to the parameter being estimated.