inference about one prop

Question 1

point estimates

Answer 1

estimates of our population parameters
use the sample mean to estimate the population mean
use sample standard deviation to estimate the population standard deviation
use the sample proportion to estimate the population proportion

point estimates don’t account for sampling variability —> samples vary

Question 2

symbols for sample mean, population mean, sample standard deviation, population standard deviation, sample proportion, and population proportion

Answer 2

sample mean : x bar
population mean : weird u
sample standard deviation : s
population standard deviation : beta
sample proportion : phat
population proportion : p

Question 3

what is the basis of hypothesis testing

Answer 3

whether the point estimate is
1. typical value ( could have happened by chance alone)
2. unusual (happened other than chance)

Question 4

null hypothesis

Answer 4

Ho
“nothing of interest” statement
any differences we see in the sample results is due to chance alone
always contains equal sign

Question 5

p-value

Answer 5

the probability of obtaining a value of the statistic as extreme or more extreme as the observed statistic when the null hypothesis is true

gives a sense of how unusual our study results are

this is the number obtained from looking at number of simulations that simulate the same sample proportion as the observed divided by the nubmer of total simulations

Question 6

Alternative hypothesis

Answer 6

Ha
“something interesting” statement
differences between sample results compared to status quo is difficult to explain as due to chance alone

Question 7

small p-value

Answer 7

there is evidence that the observed results aren’t by chance alone when null hypothesis is true

reject null

the smaller the p-value, the stronger the evidence against the null hypothesis

Question 8

large p-value

Answer 8

not enough evidence to reject the null
dail to reject the null

Question 9

p-value small enough to reject null

Answer 9

there is statistically significant enough evidence against the null hypothesis when the p-value is less than some reference value a

a. 0.01, 0.05, 0.10

if p-value is < a, reject null

Question 10

two sided hypothesis

Answer 10

Ha has p not equal to a number (so not p<n>n) meaning values can be greater or lesser than the population proportion p-value and reject the null</n>