HCD 300 - Homework 4
In a box, there are 8 red, 7 blue and 6 green balls. One ball is picked up randomly. What is the probability that it is neither red nor green?
- 1/3
In your new role as a data analyst for a large hospital chain, the CEO has asked you to explore patient outcomes at a newly built hospital ("Mountain View") versus an existing hospital ("Greenside"). She is specifically interested in seeing whether patients who are seen for heart attacks are being readmitted to the hospital more often in the new facility. You looked at data from a random sample of visits to the two hospitals during the last year. MV(yes) - 54 MV(no) - 705 MV Total - 759 GS(yes) - 16 GS(no) - 171 GS Total - 187 Total(yes) - 70 Total(no) - 876 Total - 946 If you choose a person from the survey at random, what is the probability that the person had visited the Greenside hospital and was not readmitted to the hospital within 30-days following treatment for heart attack?
- 18.08%
If a skew is more than ____ or less than ____, the skew is substantial.
- 2 and -2
A group of 262 students was polled to determine whether they exercise regularly (engaging in moderate activity for 30-60 min, 3 or more times per week). F(no) - 72 F(yes) - 58 Total - 130 M(no) - 96 M(yes) - 36 Total - 132 Total(no) - 168 Total(yes) - 94 Total - 262 If you choose a person from the survey at random, what is the probability that the person is male?
- 50.38%
If you choose a person from the survey at random, what is the probability that the person does not own a pet, given that the person is a male? F(yes) - 45 M(yes) - 32 Total(yes) - 77 F(no) - 25 M(no) - 48 Total (no) - 73 Total (F) - 70 Total(M) - 80 Total - 150
- 60%
Cleats(yes goal) - 31 Cleats(no goal) - 16 Total - 47 Cleats(yes,no goal) - 11 Cleats(no, no goal) - 9 Total - 20 Total(yes) - 42 Total(no) - 25 Total - 67 If you choose a soccer player at random, what is the probability they are wearing cleats?
- 62.69%
In your new role as a data analyst for a large hospital chain, the CEO has asked you to explore patient outcomes at a newly built hospital ("Mountain View") versus an existing hospital ("Greenside"). She is specifically interested in seeing whether patients who are seen for heart attacks are being readmitted to the hospital more often in the new facility. You looked at data from a random sample of visits to the two hospitals during the last year. MV(yes) - 54 MV(no) - 705 MV Total - 759 GS(yes) - 16 GS(no) - 171 GS Total - 187 Total(yes) - 70 Total(no) - 876 Total - 946 If you choose a person from the survey at random, what is the probability that the person visited the new Mountain View hospital site?
- 80.23%
Which is the best example of dependent probability?
- Choosing a marble out of a bag after another person drew one without replacement
Reliability is concerned with:
- Consistency
"Satisfaction" with a service may include a number of dimensions. If all of the dimensions are captured in a measurement tool/survey/questionnaire then the tool is said to have _______.
- Construct Validity
A committee of experts is convened to review all of the items on a biostatistics final exam. If the committee feels that the test is representing all areas of knowledge the test is said to have _____.
- Content Validity
When a researcher is limited by time or money they may choose this sampling method.
- Convenience Sample
In developing a new test/measure we can correlate the score to an already established valid measure. If the tests are highly correlated we say the new test has _____.
- Criterion Validity
True or False, reliability refers to whether we are truly measuring what we are trying to measure.
- False
True or False, the probability of an outcome can be a negative number.
- False
A questionnaire/tool with 10 items gathers data about drug and alcohol use. If one of the items/questions in the questionnaire does not ask about drug/alcohol use then there is a lack of ______ in this tool.
- Internal Consistency Reliability
Two graders watch a student-led presentation and score it using a rubric. If the percent agreement is high between the graders we say the test has:
- Interrater Reliability
If a distribution has a normal peak it is ____________.
- Mesokurtic
The CDC is interested in evaluating the use of an evidence-based teen pregnancy prevention program in counties across the US. They have a list of 2000 counties across all 50 states that have implemented the program of interest. How should they sample?
- Multistage Cluster Sample
A group of 262 students was polled to determine whether they exercise regularly (engaging in moderate activity for 30-60 min, 3 or more times per week). F(no) - 72 F(yes) - 58 Total - 130 M(no) - 96 M(yes) - 36 Total - 132 Total(no) - 168 Total(yes) - 94 Total - 262 If you choose a person from the survey at random, what is the probability that the person is male, given that the person does not exercise regularly?
- NOT 38.3% - 57.14% ???
In your new role as a data analyst for a large hospital chain, the CEO has asked you to explore patient outcomes at a newly built hospital ("Mountain View") versus an existing hospital ("Greenside"). She is specifically interested in seeing whether patients who are seen for heart attacks are being readmitted to the hospital more often in the new facility. You looked at data from a random sample of visits to the two hospitals during the last year. MV(yes) - 54 MV(no) - 705 MV Total - 759 GS(yes) - 16 GS(no) - 171 GS Total - 187 Total(yes) - 70 Total(no) - 876 Total - 946 If you choose a person from the sample at random, what is the probability that the person was readmitted to the hospital within 30-days following treatment for heart attack?
- NOT 7.11% - 7.4% ???
Which of the following is concerned with monitoring estimates of present performance and predictions of future performance?
- NOT Content Validity - Criterion Validity ???
Researchers want to determine the percentage of students who own iPhones and Android cell phones. They go to a popular spot on campus and ask first 100 students who pass what type of cell phone they own. What type of sampling method is this?
- NOT Random - Convenience ???
When a distribution has a tail to the left of the distribution peak it is said to be ____________ skewed.
- Negatively
When a distribution has a tail to the right of the distribution peak it is said to be ___________ skewed.
- Positively
If the mean of a set of scores is greater than the median, what can be said about the distribution?
- Positively Skewed
High school class rank is highly correlated with college GPA. This is an example of what type of validity?
- Predictive Validity
Probability is an important concept for researchers primarily because
- Researchers collect data from samples rather than populations
Hospital administrators want to determine the average satisfaction for patients receiving care in the ER over the last month. The list of all ER patients over the last month is entered into a computer program which uses an algorithm to randomly select 100 patients. Surveys are then sent to those patients. What type of sampling method is this?
- Simple Random
A researcher knows that there are more seniors at their university than freshman. They have the follwing data about the population: 19.10% - Freshman 22.19% - Sophomore 25.66% - Junior 32.28% - Senior 0.78% - Non-degree They want their sample to represent the distribution of class ranks and they want to ensure non-degree seeking students are also a representative part of their sample. What type of sample do they want?
- Stratified Random
A researcher is interested in the use of complementary medicine by residents of Phoenix across various ethnic, gender, and class categories. Which sampling method would be the best choice?
- Stratified Random Sample
______________ distribution has a skew of 0.
- Symmetrical
A brief questionnaire/test is used by primary care practitioners to assess whether patients are at risk of violence in the home. This questionnaire is used every time the patient is seen. If the results from the test are consistent over time this test has:
- Test-retest Reliability
If a measure is consistent over multiple occasions, what type of reliabiility does the test have?
- Test-retest Validity
Which of the following statements is/are TRUE about convenience samples (choose one or more):
- They are cheaper and more time efficient than other sampling methods - They are biased and non-representative of the population
In your new role as a data analyst for a large hospital chain, the CEO has asked you to explore patient outcomes at a newly built hospital ("Mountain View") versus an existing hospital ("Greenside"). She is specifically interested in seeing whether patients who are seen for heart attacks are being readmitted to the hospital more often in the new facility. You looked at data from a random sample of visits to the two hospitals during the last year. MV(yes) - 54 MV(no) - 705 MV Total - 759 GS(yes) - 16 GS(no) - 171 GS Total - 187 Total(yes) - 70 Total(no) - 876 Total - 946 True or false: The number of patients readmitted to the hospital within 30-days following treatment for heart attack was greater at Mountain View than at Greenside
- True
Samples should be ___________________ (choose one or more) when considering the population from which they were drawn.
- Unbiased - Representative
If you choose a person from the survey at random, what is the probability that the person owns a pet? F(yes) - 45 M(yes) - 32 Total(yes) - 77 F(no) - 25 M(no) - 48 Total (no) - 73 Total (F) - 70 Total(M) - 80 Total - 150
51.33%
