STSCI Prelim 2 Vocab

binomial distribution

probability of X successes in N independent + identical trials

poisson distribution

probability that X events occur independently + randomly in space/time

goodness-of-fit

used to test whether the observed data matches the expected probability model

null distribution

probability distribution of potential values of the test statistic if the null hypothesis is true

p-value

probability of an expected/unexpected value if the null hypothesis is true

significance level/alpha

probability that is helpful as (maybe required) criteria to evaluate result

test statistic value

value compared to the null distribution to calculate p-value

type I error

rejecting a null hypothesis that is true = alpha

type II error

accepting a null hypothesis that is false = beta

power

probability of rejecting a null hypothesis that is false = 1 - beta; increases with sample size

statistical inferences

point estimate vs interval estimate vs hypothesis test

degrees of freedom

number of values that can vary for the calculation

test of single proportion

used to compare sample proportion w/ the population

null distribution of test of single proportion

binomial distribution

test of association

used to determine if there is a relationship b/w 2 groups

null distribution of test of association

chi-squared distribution

goodness-of-fit for poisson distribution

used to determine whether events happen in a poisson distribution

1 - pchisq(chi-squared value, df)

finds the p-value using chi-squared value + df

qchisq(1 - alpha, df)

finds the critical value using alpha + df

pnorm(x)

finds the probability of x and less

qnorm(x)

finds the percentile of x and less