EXTRA CREDIT FOR FINAL EXAM Flashcards
What does Variability do?
Makes it easier to detect differences in the treatment outcomes.
Practice Problem A study found correlation r=0.61 between the sex of a worker and his or her income. You conclude that
A. Women earn more than men on the average.
B. Women earn less than men on average.
C. An arithmetic mistake was made; this is not a possible value of r.
D. This is nonsense because r makes no sense here.
D. This is nonsense because r makes no sense here.
Block
group of experimental units or subjects that are similar in ways that are expected to affect the response to the treatments
What is the explanatory variable in the LSRL formula?
x
What is the general equation for a least square regression line
ŷ=a+bx
Controls allows ______?
The experimenter to eliminate confounding effects of lurking variables.
What is a Matched Pairs Design?
A type of block design used when an experiment only has two treatments and participants can be grouped into pairs based on a variable. Within these pairs, participants are randomly assigned to treatments.
What is a two way table?
IDK, There is a row, column. Add all the number of column and row will give the total amount of the study.
What are the four types of quantitative graphs covered in class?
Stem Plot
Histogram
Dot Plot
Ogive
What are the possible measures of spread?
Range
IQR
Variance
Standard Deviation
If a player rolls two dice and gets a sum of 2 or 12 he wins $20. If the person gets a 7 he wins $5. The cost to play the game is $3. Find the expectation of the game.
Expectation=the meanE(x)= 1.165
Define simulation
The imitation of chance behavior based on a model that reflects the experiment.
What is a Convenience Sample?
A poor sampling technique in which the data is obtained in the most convenient way possible, which will not account for any lurking variables in the sample. EX: A teacher asking only the students who will be in his room during the day.
What type of graph is this?
continuous density curve
What is the 5th and final step in designing a simulation?
State your conclusions
Where is b found in a computer printout?
Directly below a
What is IQR?
What is its equation?
When do you find the IQR for spread?
- Inner Quartile Range
- Q3-Q1=IQR
- You use it when the shape of the graph is skewed
Placebo effect
Dummy treatment that has no physical effect
Comparative Experiment
Treatment–ObservationObservation 1–Treatment–Observation 2
Independence
Is P(A) × P(B) = P(A and B)?Is P(B|A) = P(B)?Is P(A|B) = P(A)?If yes then the events are independent.
What type of graph is this?
discrete density curve
What does “ŷ” mean?
Predicted value/outcome
What is the z-score equation?
z = (x - μ) / σx = x-valueμ = meanσ = standard deviation
What is an example of under coverage?
Sample Houses, prisoners or students
What are the symbols for Correla2tion and Coefficient of Determination?
R = Correlation
R2 = Coefficient of Determination
Central is playing Centennial. If Central’s 1st quarterback plays they have a 75% of winning. if they play the backup QB their chances drop to 40%. The chance of the 1 QB playing is 70%. a) Probability of winning the game? b) If central won was was the probability the backup QB played?
a) P(winning)= .645b) P(Backup QB/ Winning)= .186
In the binomial setting, is the number of observations fixed or variable?
The number of observations is fixed in a binomial setting.
What is a Completely Randomized Design?
Participants are randomly assigned to treatments.
How do you find the residual?
y-ŷ
If the graph of your data is skewed, what center and measure of spread should you use?
Center: Median
Measure of Spread: IQR
Why is this an example of matched pairs design?
The participants are matched by type of car.
What is a wording bias?
the wording of questions can cause bias
which of the following is Quantitative?
a. age
b. time
c. gender
d. number of girls in a class
e. number of people in a class
a and e
Practice problem:Sarah got a test score of 77%- The standard deviation of the test was 7%- Sarah’s z-score was .57What is the mean of the class??
73%
what is the difference between geometric cdf and geometric pdf?
cdf= winning on a certain trial pdf= winning on or before a certain trial
95% of the observations fall within how many standard deviations of the mean?
2
Graph has no peak and all bars of data are the same height.
Uniform
Subject
Unit is a person
Graph has one peak and data is on the right.
Skewed Right
numerical outcome of a probability that is determined by chanceex) roll of a die, or flipping a coin
random variable
Describe the four conditions that describe a Binomial setting
- 2 outcomes
- Fixed number of trials
- Each trial is independent.
- Probability of success is the same everytime.
Probability of getting accepted to Yale is 0.7 and the probability of being accepted to Princeton is 0.6. Probability of getting accepted to both is 0.4. a) Probability of getting accepted to one school? b) Not accepted to either school?
a) 0.9b) 0.1
Conditional Probability Formula
P(A|B) = P(AnB)/P(B)
Find the probability of getting a success on the 5th trial with 10% chance of success.
(1-0.1)^4•0.1
Individuals that do not follow the pattern of the data. These include values that are very small or very large.
Outliers
How can a study be biased?
A study is biased if it systematically favors certain outcomes.
What is the equation to find “b”?
b=r(Sy/Sx)
Graph has one peak and the data is on the left side.
Skewed Left
can be measuredex) weight of m&m’s
continuous
What quantitative graph divides its x-values into groups and then adds the previous y-values quantity to its own?
Ogive
What is a z-score?
Standardized variable, the amount of standard deviations away from the mean
What is Multistage Sampling?
A using multiple sampling to create a sample.
What is a Voluntary Response Sample?
A poor sampling technique in which the individuals elect to be a part of the survey. It is a poor sampling technique because the only people who volunteer, will be the people who feel the very strongest on the matter.
what is the area under any density curve?
1
What is the variable name of constant coefficient in the LSRL formula?!
a
can be countedex) number of red m&m’s in a bag
discrete
What is the center?
The middle of the distribution, first located by finding the highest peak. It is measured by mean, median, or mode.
What is mean; its equation?
The average; the sum of the data divided by the number of numbers.
What is the slope in the LSRL formula?
b
Graph has one peak and data is on both sides.
Symmetric