STAT 503 Final EXAM Comprehensive
Questions (Frequently Tested) with
Verified Answers
Is a quantitative variable always measured in numbers? - Answer: Yes
Is any measurement that you record from a sample a variable? - Answer: False
What is a statistic? - Answer: 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... - Answer: Left
What is sensitive to outliers? - Answer: Median
Formula to calculate standard deviation - Answer: s = sqrt(sum(x1-xbar)^2 / n-1)
How to calculate degrees of freedom? - Answer: n-1
What is the first quartile? - Answer: Median of lower half
What is the third quartile - Answer: Median of upper half
What is included in a box plot summary? - Answer: Q0 = minimum
Q1 = median of lower half
Q2 = median
, Q3 = median of upper half
Q5 = maximum
What is the the interquartile range (IQR)? - Answer: Q3 - Q1 (shown inside box plot)
What is an outlier? - Answer: Any data that is Q3 + 1.5IQR or Q1 - 1.5 IQR
When is a phenomenon random? - Answer: When it has uncertain outcomes in a short run
(sample) but show regular distribution in a long run (population)
What is an outcome? - Answer: Observation of a variable
What is a probability model? - Answer: 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) - Answer: P(AB) = P(A) P(B|A) = P(B) P(A|B)
What is the addition rule? (disjoint) - Answer: P(A or B) = P(A) + P(B) - P(AB)
If A and B are disjoint, the must be dependent. - Answer: TRUE
Why is a probability tree diagram used? - Answer: To show multiple variables according to
stages (the order that they happen)
What is written on each segment in a probability tree? - Answer: A conditional probability
Questions (Frequently Tested) with
Verified Answers
Is a quantitative variable always measured in numbers? - Answer: Yes
Is any measurement that you record from a sample a variable? - Answer: False
What is a statistic? - Answer: 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... - Answer: Left
What is sensitive to outliers? - Answer: Median
Formula to calculate standard deviation - Answer: s = sqrt(sum(x1-xbar)^2 / n-1)
How to calculate degrees of freedom? - Answer: n-1
What is the first quartile? - Answer: Median of lower half
What is the third quartile - Answer: Median of upper half
What is included in a box plot summary? - Answer: Q0 = minimum
Q1 = median of lower half
Q2 = median
, Q3 = median of upper half
Q5 = maximum
What is the the interquartile range (IQR)? - Answer: Q3 - Q1 (shown inside box plot)
What is an outlier? - Answer: Any data that is Q3 + 1.5IQR or Q1 - 1.5 IQR
When is a phenomenon random? - Answer: When it has uncertain outcomes in a short run
(sample) but show regular distribution in a long run (population)
What is an outcome? - Answer: Observation of a variable
What is a probability model? - Answer: 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) - Answer: P(AB) = P(A) P(B|A) = P(B) P(A|B)
What is the addition rule? (disjoint) - Answer: P(A or B) = P(A) + P(B) - P(AB)
If A and B are disjoint, the must be dependent. - Answer: TRUE
Why is a probability tree diagram used? - Answer: To show multiple variables according to
stages (the order that they happen)
What is written on each segment in a probability tree? - Answer: A conditional probability
