STAT100 symbols and meanings

μ

population mean

σ

population standard deviation

P

population proportion

p̂

sample proportion

N

sample size

x̄

sample mean

s

sample standard deviation

α

significance level

Ho

Hypothesis null

Ha

Hypothesis alternative

p-value < significance level

reject the null hypothesis

p-value < significance level

DONT reject the null hypothesis

Two sided hypothesis

when the null hypothesis is EQUAL or DOESNT EQUAL

One sided hypothesis

when the null hypothesis is EQUAL or GREATER/LESS THAN

Positive Z-score

the data value is larger than the mean

Negative Z-score

the data value is smaller than the mean

skewed left

mean < median

skewed right

mean > median

symmetric

mean = median

IQR

Q3-Q1

Q1

25% of data below it

Q2

50% of data below it

Q3

75% of the data below it

Hypothesis Test (Step 1)

Write Ho and Ha

Hypothesis Test (Step 2)

Test conditions using n*po≥10 and n(1-po)≥10

Hypothesis Test (Step 3.1)

Find sample proportion

p̂= #individual/sample size

Hypothesis Test (Step 3.2)

Plug p̂ into test statistic formula

Hypothesis Test (Step 4)

Find test statistic in Z table

IF the p-value is two sided, multiply by 2

Hypothesis Test (Step 5)

Compare P-value w/ the Significance level

p < s [reject Ho]

p > s [DONT reject H0]