Studies & Experimental Design
Researchers observe outcomes without imposing an treatment called.
Observation Study
The true information / numerical values about a population are called what.
Parameters (mean, and standard deviation)
_________ is a graphical display of the relationship between two quantitative variables.
Scatterplots
________ The equation of a straight line (any straight line) drawn through the data.
Linear Model
The ______________ says that, in the long run, as we repeat a random process over and over, the proportion (or percentage) of times that an event occurs gets closer to one number.
The Law of large number's (LLN)
Every Experiment has what?
Explanatory Variable / Factor, Response Variable, Levels, and Treatments
What is any methodical failure of a sampling method to represent a population called.
Bias
What are the three different types of strength of two variables' association is based on how close together the data points are on the scatterplot.
Strong- very close together
Moderate- somewhat close together
Weak- far apart from each other
What is the equation for linear models and residuals?
y=a+bx
a= intercept
bx= slope
The nonexistent "____________" says that an outcome of a random event that hasn't occurred in many trials "dur" to occur at some point.
"Law of Average"
What are the principles of a well-designed experiment?
C- Control/eliminate as many confounding variables as possible.
R- Random Assignment to eliminate bias.
R- Replication, must be easily followed for replication.
C- Compare 2 or more variables to give a result.
What type of bias is it when individuals chosen for a smaple don't respond, refuse to respond, or can't be reached called.
_____________ The variable that we think will explain or predict the other variable is called the what?
Explanatory Variable
For a certain x-value, a ______________ is the y-value of the point on the linear model?
Predicted Value
What is the equation for the probability of an even?
P (event a) = # of outcomes of event a divided by total # of possible outcomes
Everything is randomly assigned to help balance the effects of possible unknown confounding variables that aren't being controlled is called what.
Completely Randomized Design
What are the types of bias?
1. Under coverage Bias
2. Nonresponse Bias
3. Response Bias
What are the three unusual features of a scatterplot are the same as those on other graphs.
Outliers- value far away from the rest
Gaps- space in the data
Clusters- big groups of dots
What is the answer to y-hat = 2 + 0.9 (12) = ______.
12.8g
Example Problem:
You have a bag of 8 marbles: 2 red, 3 green, 1 blue, and 2 yellow.
What is the P(red) and the P(not blue)
P (red) = 2/8 = 1/4 and the P (not blue) = 1 - 1/8 = 7/8
Some Experiments have what?
Placebo, Control Group, Single Blind, and Double Blind
What type of bias is it called when something in the survey's design influences responses, confuses individuals, or leads individuals to respond in a certain way?
Response Bias
What are the two types of trends of two variables' association refers to the direction the data points appear to move in.
Positive- dots move up and right
Negative- dots move down and right
The set of outcomes that are NOT in the event A is called the __________ of A.
Complement