What normality formula is used for categorical data (proportions)?
np ≥ 10 n(1-p) ≥ 10
What type of interval or test is used in matched-pair datasets?
T intervals and T tests
What normality formula is used for quantitative data (means)?
n ≥ 30 OR population distribution is normal OR check graphs
What is the calculator function for checking normality graphs (only for problems with means)?
2nd stat plot
What type of problem uses exclusively Z tests and Z intervals?
Categorical data/proportions
When is df = n-1 true?
Only in problems with one sample/proportion
When is t* used?
Only in problems that ask for a confidence interval
How do we find t*?
2nd VARS ----> invT
When do we use Z tests in quantitative problems (means)?
If we know σ
What is the formula to find T scores?
(x-u)/(S/sqrtN)
When do we use tcdf?
When conducting T tests only. It's used to find the p-value instead of normalcdf
How do you calculate a Z interval?
x +/- z*(s/square root of n)
How do you calculate an T interval?
x +/- t*(s/square root of n)
How do we find z*?
z = (x - μ) / (σ/sqrt of n)
How do degrees of freedom (df) affect t distributions?
Higher df = smaller variance/taller curve
What is a Type 1 error?
False positive
What is a Type 2 error?
False negative
How do we write the process of finding a p-value?
P(x=x) = P(tdf=t score) = tcdf(LB
Where do we find z*?
The last row of the table on the formula sheet