Question 1. Statistical probability is most closely associated with which of the following types of statistics?
Descriptive Statistics
The Mean, Median and Mode
Inferential Statistics
Standard deviation
None of the above
Question 2. Two experienced and competent researchers conducted the exact same study in two different cities, and on the same type of patients (essentially the same population). One got very different results than the other. Which of the following is the most likely reason that happened?
Poor data collection
Sampling variability
Low statistical power made it impossible to measure the dependent variable
Patients in one city were very different from patients in the other city
Question 3. Which of the following sampling procedures represents non-probability sampling?
The researcher obtains a sample of subjects from his own patient group because they are easy to find.
The researcher first splits the population into different groups (or strata) and then randomly samples from each group.
The researcher randomly samples from the entire population.
The researcher first assigns a number to all potential subjects, and then selects every 5th person in the population in order to obtain a sample of 1,500 subjects.
Question 4. The specificity of a test is defined as:
The probability that a person who does not have a streptococcal infection will have a negative streptococcal screen
The probability that an infected person will test negative.
The probability that a healthy teenager will get into a fatal car accident
The probability that a person with active tuberculosis (TB) will have a positive skin test for TB.
Question 5. Which of the following paired events (or things) would be considered statistically independent?
My daughter having a nose that is shaped just like mine.
My husband and I having the same blood type.
Two students in the same class both get chicken pox.
A student who did not have time to study failing an exam.
Question 6. The researcher is conducting a study to predict whether or not subjects with a positive mammogram actually have breast cancer. The two possible outcomes are "no, the breast is healthy" versus "yes, this person has breast cancer". Which of the following distribution models should the researcher use?
A Poisson Distribution
The Normal Distribution
A flat distribution
A binomial distribution
Question 7. The Central Limit Theorem states that if I have a large number of samples from a population, the means of the samples will form a normal distribution, no matter what the distribution of the original population is. Why is this important?
It allows us to generalize from a sample to a population
It means that all distributions are really normal distributions.
It proves that all samples are good indicators of the population.
It means that researchers can reliably generalize from even very small samples to the full population.
Question 8. I have measured the length in inches of all newborns for this year, and the mean length is 20 inches with a standard deviation of 0.9 inches. What can you say about a baby whose length is 22.5 inches?
This baby is extremely long compared with the other babies because it is beyond three standard deviations of the mean.
The baby's length is normal because it is less than 1 standard deviation above the mean.
This baby's length is within the normal range of plus or minus 3 standard deviations of the mean.
This baby is an extreme outlier because its length is more than 4 standard deviations above the mean.
Question 9. Which of the following statements best describes the meaning of "estimation" in statistics?
Estimation determines the most likely value for a population number, such as a population mean.
Estimation is used to determine how accurately the sample matches the population.
Estimation is used to determine how consistently the independent variable was applied to subjects in the study.
Estimation is used to determine how large of a sample size needed in the study.
Question 10. Suppose we have a sample of 245 patients who have undergone gastric bypass surgery. Their average weight loss 6 months after surgery is 62 pounds, with a standard deviation of 9.4 pounds. Which of the following patients is an outlier?
The patient who lost 40 pounds
The patient who lost 20 pounds
The patient who lost 66 pounds
The patient who lost 90 pounds
Question 11. If, from a census data report, we know that the average age of women when they have their first baby is 22.4, then it is accurate to say the value, 22.4, is which of the following?
A sample statistic
A population parameter
A sample mean
A population statistic
Question 12. A new screening test for a disease has a sensitivity score of .89. Which of the following statements are true of this test?
The test will give a negative result for 89% of the people who do not have the disease
The test will give a false positive result for 11% of the people who do not have the disease.
The test will give an accurate negative result for 89% of those who do not have the disease.
The test will accurately give a positive score for 89% of the people who do have the disease.
Question 13. Which of the following statements is true of sensitivity?
For a very sensitive test, virtually all the sick people will test positive.
For a very sensitive test, virtually all the healthy people will test negative.
If a test is more than 98% sensitive, then specificity doesn't matter.
Specificity is the opposite of sensitivity.
Question 14. If a screening test is 10% sensitive and 99% specific, it will do which of the following?
It will almost always test positive for people who have the disease.
It will almost always test negative for people who have the disease.
It will almost always test negative for people who do not have the disease.
It will almost never test positive for people who do not have the disease.
Question 15. If a researcher randomly selects subjects from a population and assigns them randomly to either an experimental or control group, making sure the two groups have the same number of subjects, what is true of the samples?
The sample is a matched pair sample
The experimental and control groups constitute dependent, probability samples.
The experimental and control groups constitute an independent, probability sample.
The experimental and control groups constitute an independent, non-probability sample.
Question 16. The researcher plans to use a normal distribution probabillity model for the study statistical analysis. Which of the following variables in her dataset best fits the assumptions of the normal distribution model?
Ethnicity of the subject (Caucasian, African American, Hispanic, Asian, Pacific Islander)
Gender (male versus female) of the subject
Disease that caused death (stroke, heart attack, hemorrhage, pancreatic cancer)
Age at death