STAT 503 FINAL EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED
Is a quantitative variable always measured in numbers?
Yes
Is any measurement that you record from a sample a variable?
False
What is a statistic?
The measure that is taken from the whole sample as a summary of the sample
Sample data skewed to the left, then longer tail is at the...
Left
What is sensitive to outliers?
Median
Formula to calculate standard deviation
s = sqrt(sum(x1-xbar)^2 / n-1)
How to calculate degrees of freedom?
n-1
What is the first quartile?
Median of lower half
What is the third quartile
Median of upper half
What is included in a box plot summary?
, Q0 = minimum
Q1 = median of lower half
Q2 = median
Q3 = median of upper half
Q5 = maximum
What is the the interquartile range (IQR)?
Q3 - Q1 (shown inside box plot)
What is an outlier?
Any data that is Q3 + 1.5IQR or Q1 - 1.5 IQR
When is a phenomenon random?
When it has uncertain outcomes in a short run (sample) but show regular distribution in
a long run (population)
What is an outcome?
Observation of a variable
What is a probability model?
A mathematical description of a random phenomenon consisting of 2 parts (sample
space and way of assigning probability to event)
What is the multiplication rule? (independent)
P(AB) = P(A) P(B|A) = P(B) P(A|B)
What is the addition rule? (disjoint)
P(A or B) = P(A) + P(B) - P(AB)
If A and B are disjoint, the must be dependent.
TRUE
COMPLETE SOLUTIONS VERIFIED
Is a quantitative variable always measured in numbers?
Yes
Is any measurement that you record from a sample a variable?
False
What is a statistic?
The measure that is taken from the whole sample as a summary of the sample
Sample data skewed to the left, then longer tail is at the...
Left
What is sensitive to outliers?
Median
Formula to calculate standard deviation
s = sqrt(sum(x1-xbar)^2 / n-1)
How to calculate degrees of freedom?
n-1
What is the first quartile?
Median of lower half
What is the third quartile
Median of upper half
What is included in a box plot summary?
, Q0 = minimum
Q1 = median of lower half
Q2 = median
Q3 = median of upper half
Q5 = maximum
What is the the interquartile range (IQR)?
Q3 - Q1 (shown inside box plot)
What is an outlier?
Any data that is Q3 + 1.5IQR or Q1 - 1.5 IQR
When is a phenomenon random?
When it has uncertain outcomes in a short run (sample) but show regular distribution in
a long run (population)
What is an outcome?
Observation of a variable
What is a probability model?
A mathematical description of a random phenomenon consisting of 2 parts (sample
space and way of assigning probability to event)
What is the multiplication rule? (independent)
P(AB) = P(A) P(B|A) = P(B) P(A|B)
What is the addition rule? (disjoint)
P(A or B) = P(A) + P(B) - P(AB)
If A and B are disjoint, the must be dependent.
TRUE
