What did Mr. Purvis major in?
Statistics and Music
how do you calculate the mean of random variable X-Y
mean X - mean Y
What is the interpretation of a 95% confidence level?
If we did this test many many times, we would expect 95% of our confidence intervals to contain the true parameter
Which rule tells you how much data lies between 1, 2, and 3 standard deviations of a normal curve?
What is the 68-95-99.7 rule?
What value is interpreted as how much of the variation in y can be explained by x
What is the coefficient of determination (or r squared)?
why do we need random assignment in experiments?
generalization to the population
What does it mean for 2 variables to be independent
One happening does not affect the probability of the other happening
The conditions to use this test include all expected counts be greater than or equal to 5.
What is the chi-square test?
How do you calculate outliers for a box plot?
x < Q1- 1.5IQR
x > Q3+ 1.5IQR
What in a residual plot will tell us if there is a linear relationship between two variables?
No pattern
So that we an imply causation between our explainatory and response variables
what are the three conditons to check when doing a test for a single proportion
Random assignment-
10%- n< (1/10)N
Large counts- np>10 n(1-p)>10
What does DUFS stand for and what does each word mean?
Direction
Unusual Feature
Form
Strength
What is a the difference between a cluster sample and a stratified random sample?
in cluster sampling you randomly select entire groups and include all units of each group in your sample. However, in stratified sampling, you select some units of all groups and include them in your sample
The standard deviation of random variable x+y is calculated how?
adding the variances of x and y then square rooting it
what is the equation for a confidence interval for a population mean?
x-bar (+/-) t*(sd/sqrt(n))