Stats Final Review

• A

• B

• C

• D

• E

• A

• B

• C

• D

• E

If Gonzalo's score is 87, the class average is 82, and the SD is 4, what is Gonzalo's Z-score?

• -1.25

• +1.25

• +1.20

• +1.02

Let x be a random variable that represents the Red Blood Cell(RBC) count in millions per cubic millimeter of whole blood. Then x has a distribution that is approximately normal, and for the population of healthy female adults, the mean of the distribution is about 4.8. Suppose that a female patient has taken six laboratory blood tests over the past several months and the RBC count data sent to the patient’s doctor were 3.5 4.2 4.5 4.6 3.7 3.9 Does the given data indicate that the population mean RBC count for this patient is lower than 4.8? Use alpha = 0.05

• Yes, the population mean RBC count is lower than 4.8

• No, the population mean RBC count is not lower than 4.8

• There is not enough evidence to say either way.

In their advertisements, a new diet program would like to claim that their methods result in a mean weight loss of more than ten pounds in two weeks. In order to determine if this is a valid claim, they hire an independent testing agency that then selects twenty-five people to be placed on this diet. The agency should be testing the null hypothesis H₀: m = 10 and the alternative hypothesis

• Ha: μ < 10

• Ha: μ > 10

• Ha: μ ≥ 10

• Ha: μ ≤ 10

A test is given that has a mean of 70 and a standard deviation of 13. If a student's Z-score is +1, the student's score before conversion was:

• 70

• 83

• 57

• Cannot be determined from the information given.

The mean and standard deviation of a population are 200 and 20, respectively. 
What is the probability of selecting one data value less than 190?

• 69%

• 42%

• 31%

• 58%

Find the area under the standard normal curve to the right of z = -2.67.

• 0.0869

• 0.9962

• 0.0008

• 0.1234

A 90% confidence interval for a population mean is determined to be 800 to 900. If the confidence is increased to 95% confidence while the sample statistics and sample size remain the same, the confidence interval

• becomes wider

• becomes narrower

• does not change

Which z-value is used for a 95% confidence interval?

• 1.65

• 1.96

• 2.58

• 2.33