Probability and Statistics, WGU C955 Questions and Answers (Graded A+)

Probability and Statistics, WGU C955
Questions and Answers (Graded A+)

Boxplot - ANSWER-an image that has min, Q1, median, Q3, max

Histogram - ANSWER-A graphical representation -- bars, measuring the frequency
within each interval

Skewed right - ANSWER-Not a symmetric distribution, the tail is on the right, i.e. extra
stuff on the right

Measures of center - ANSWER-Median, the mean (and mode)

Measures of spread - ANSWER-Range, IQR & standard deviation

Standard Deviation Rule - ANSWER-68% of the data are within 1 standard deviation,
95% are within 2, 99.7 are within 3 standard deviations from the mean.

For skewed data, use these for center and spread - ANSWER-In this situation, we use
median (for center) & IQR (for spread)

Explanatory variable - ANSWER-In a study, what we think is the "cause"

Response variable - ANSWER-In a study, what we think is the "effect"

Scatter plot - ANSWER-A graphical representation of Q -> Q

Two way table - ANSWER-A graphical representation of C -> C

Side-by side box - ANSWER-A graphical representation of C -> Q

Linear relationship - ANSWER-"shaped like a line"

Correlation coefficient, r - ANSWER-Between -1 and 1; measures how close the points
are to the line and if the trend is uphill (positive) or downhill (negative).

r = -0.2, for example - ANSWER-This is an example of a correlation coefficient that
represents a weak negative correlation.

r = 0.9, for example - ANSWER-This is an example of a correlation coefficient that
represents a strong positive correlation.