Easy Level 2 Flashcards
SOCS
Shape - skewed left or right, symmetric, uniform, unimodal, bimodal
Outliers -
Center - mean or median
Spread - IQR, range, standard deviation
Interpret y-hat LSRL
Y hat is the estimated or predicted y value for a given x value
Chi squared conditions
Random
10%
Large counts - at least 5
Inference for means
Conditions
Random
10%
Normal/ large sample - at least 30 or more for approx normal sample
Inference for regression
Conditions
Linear Independence - no replacement Normal - dots are along regression line Equal sd Random
Inference for proportions conditions
Random
10%
Large counts - np hat> equal to 10 and n(1- p hat)> equal to 10
Percentile
a number where a certain percentage of scores fall below that number
If you know that your score is in the 90th percentile, that means you scored better than 90% of people who took the test.
Interpret r
Talk about r correlation levels in strength too
Correlation measures the strength and direction of linear relationships between x and y
R always between -1 and 1
Close to zero = very weak
Close to 1 = very strong
Interpret z score
Equation too
Value-mean/ standard dev
Describes howmany stand devs a value falls away from the mean of the distribution and in what direction.
Surprising
Interpret LSRL Slope “b”
For every one unit in the x variable the y variable is predicted to increase/ decrease by units
Interpret LSRL y intercept “a”
When the variable is zero, the y variable is predicted to be _____
Interpret r2
____% of the variation in y is accounted for by the LSRL of y on x
OR
____% of the variation in y is accounted for by using the linear regression model with x as the explanatory variable
Interpret LSRL “s”
S= ___ standard deviation of the residuals
It measures the typical distance between the actual y values and their predicted y values in a regression setting
