WGU C784 Statistics FULL COURSE REVIEW Questions
with verified answers
3 Types of Percentages on a Two-Way Frequency Table Ans✓✓✓ OVERALL% -
(aka Relative Frequencies) When all of the counts are divided by the overall total
CONDITIONAL ROW% - when the explanatory variable is in rows; calculated by
dividing the joint frequencies of each row by the row total
CONDITIONAL COLUMN% - when the explanatory variable is in the columns;
calculated by dividing joint frequencies of each column by column total
5 Number Summary Ans✓✓✓ Min - Q1 - Median - Q3 - Max
Because "at least one X" and "no X" are complements, it is always true that
Ans✓✓✓ P(at least one X) = 1 - P(no X)
Center & Spread Measures Ans✓✓✓ SYMMETRIC - Mean (center) / Standard
Deviation (spread)
SKEWED - Median (center) / IQR (spread)
CATEGORICAL - Mode (center) / no spread
Complementary Event Ans✓✓✓ an event NOT happening
, Conditional Probability of Dependent Events Ans✓✓✓ P(B | A) = probability of
event B happening given that A occurred
P(B | A) = P(A and B)/P(A) this is "both" divided by "given"
Correlation Coefficient Ans✓✓✓ aka "r", describes the direction and strength of
the relationship of variables on a scatterplot.
Between -1 and +1
0 = no correlation
-1 = perfect negative correlation
1 = perfect positive correlation
Define Explanatory vs Response Variable Ans✓✓✓ EXPLANATORY VARIABLE
(x/independent) - presumed to possible cause change in the response variable
RESPONSE VARIABLE (y/dependent) presumed to be affected by the explanatory
variable
Disjoint Event Ans✓✓✓ Event that cannot overlap or occur at the same time.
P (A and B) = 0
P(A and B) = P(A) + P(B)
with verified answers
3 Types of Percentages on a Two-Way Frequency Table Ans✓✓✓ OVERALL% -
(aka Relative Frequencies) When all of the counts are divided by the overall total
CONDITIONAL ROW% - when the explanatory variable is in rows; calculated by
dividing the joint frequencies of each row by the row total
CONDITIONAL COLUMN% - when the explanatory variable is in the columns;
calculated by dividing joint frequencies of each column by column total
5 Number Summary Ans✓✓✓ Min - Q1 - Median - Q3 - Max
Because "at least one X" and "no X" are complements, it is always true that
Ans✓✓✓ P(at least one X) = 1 - P(no X)
Center & Spread Measures Ans✓✓✓ SYMMETRIC - Mean (center) / Standard
Deviation (spread)
SKEWED - Median (center) / IQR (spread)
CATEGORICAL - Mode (center) / no spread
Complementary Event Ans✓✓✓ an event NOT happening
, Conditional Probability of Dependent Events Ans✓✓✓ P(B | A) = probability of
event B happening given that A occurred
P(B | A) = P(A and B)/P(A) this is "both" divided by "given"
Correlation Coefficient Ans✓✓✓ aka "r", describes the direction and strength of
the relationship of variables on a scatterplot.
Between -1 and +1
0 = no correlation
-1 = perfect negative correlation
1 = perfect positive correlation
Define Explanatory vs Response Variable Ans✓✓✓ EXPLANATORY VARIABLE
(x/independent) - presumed to possible cause change in the response variable
RESPONSE VARIABLE (y/dependent) presumed to be affected by the explanatory
variable
Disjoint Event Ans✓✓✓ Event that cannot overlap or occur at the same time.
P (A and B) = 0
P(A and B) = P(A) + P(B)
