Stats midterm practice muliple choice questions
No two histograms share the same boxplot unless the histograms are the same
False
There can be different amounts of data in each section of a box plot
False
the probability of event B given that event A has occurred is denoted by P(A|B).
False, P(B|A)
Suppose the percentage of Corvette owners who are women is 25% and the percentage of Corvette owners who are men is 75%. True or False: Corvette ownership is independent of gender.
False, they are not equal
If the probability of event A changes once you know that event B has occurred, then events A and B must be
Not independent, (We know by what we are given that P(B|A) is not equal to P(A). This means knowing B occurred affected P(A),so they are not indpendant
if X and Y change what else will?
The slope of the regression line the Y intercept of the regression line
SSE is equal to what?
The sum of squares for error for any line going through the data
A and Ac are disjoint events
True
a confounding variable can cause the results of a two way table to reverse when it is added to the set
True
When you break down data into two groups, for example males and females, and compare their opinions, you are finding and comparing conditional probability
True (because you are comparing one or more events)
Suppose A and B are two independent events for which P(A/B) = 0.20 and P(B) = 0.60. Can you find P(A) with the given information?
YES, P(A|B)= P(A), if they are independent you do not need P(B)
If independent
p(A|B)=P(A)
If the correlation is 0 you know there is no relationship between X and Y
False
R= -7 what is the coefficient of determination
49 because r squared cannot be negative
What does it mean for a sample to be truly random?
Every sample of the same size has the chance of being selected.
Suppose P(A) = .5 and P(B) = .2. Then P(A and B) must equal .10.
FALSE, only if A and B are independent
The cells within a two-way table represent conditional probabilities.
FALSE, they are "And" probabilites
An influential point is defined to be a point with a large residual
False
How do we use correlation and COD ( R squared)
R squared measures any kind of relationship ; correlation only measures linear relationships