Formulas

Question 1

x-µ

σ

Answer 1

formula for z-score

Question 2

Σx+P(X=x)

Answer 2

expected value of a random variable

Question 3

n!

k!(n-k)!

Answer 3

number of ways k successes can occur in n trials

Question 4

b_o+b₁x

Answer 4

equation of regression line

Question 5

r_sx^sy =

Answer 5

b₁ (slope)

Question 6

ybar-b₁xbar

Answer 6

b_o(y-intercept)

Question 7

σ

sqrt of n

Answer 7

sample standard deviation

Question 8

sqrt( pq/n )

Answer 8

standard deviation of sampling distribution

Question 9

68-95-99

Answer 9

confidence intervals

Question 10

phat +/- z*sqrt( phat*qhat/n)

Answer 10

confidence interval for a proportion

Question 11

ybar +/- t_n-1 s/sqrt(n)

Answer 11

confidence interval for µ

Question 12

p(1-p)(z²/ME²)

Answer 12

sample size calculation

Question 13

phat-p_o / sqrt( p_o(1-p_o)/n)

Answer 13

approximately standard normal

Question 14

ybar-µ_o / s/sqrt(n)

Answer 14

test statistic for mean

Question 15

dbar / (std dev/sqrt(n))

Answer 15

test statistic for difference of means

Question 16

(z*s / ME)²

Answer 16

sample size calculation

Question 17

ybar₁-ybar₂ +/- t_df sqrt( s₁²/n₁ + s₂²/n₂)

Answer 17

confidence interval for difference of means

Question 18

phat₁-phat₂ +/-

z * sqrt( (phat₁*qhat₁/n₁) + (phat₂*qhat₂/n₂)

Answer 18

confidence interval for comparing two proportions

Question 19

b₁ +/- t_n-2 * SE(b₁)

Answer 19

confidence interval for the regression slope

Question 20

(ybar₁-ybar₂) / sqrt( s₁²/n₁ + s₂²/n₂)

Answer 20

test statistic for difference of two means

Question 21

phat₁-phat₂ / sqrt (phat1*qhat1/n1) + (phat2*qhat2/n2)

Answer 21

test statistic for comparing two proportions

Question 22

y₁+y₂ / n₁+n₂

Answer 22

pooled estimate of the proportion

Question 23

b₁-ß₁ / SE(b₁)

Answer 23

test statistic for the regression slope

Question 24

Σ (obs-exp)² / exp

Answer 24

test statistic for goodness of fit and homogeneity

Question 25

(#rows-1) * (#columns-1)

Answer 25

degrees of freedom for goodness of fit and homogeneity

Question 26

1.645 1.96 2.576

Answer 26

z-scores for confidence intervals

Question 27

formula for z-score

Answer 27

x-µ

σ

Question 28

expected value of a random variable

Answer 28

Σx+P(X=x)

Question 29

number of ways k successes can occur in n trials

Answer 29

n!

k!(n-k)!

Question 30

equation of regression line

Answer 30

b_o+b₁x

Question 31

b₁ (slope)

Answer 31

r_sx^sy =

Question 32

b_o(y-intercept)

Answer 32

ybar-b₁xbar

Question 33

sample standard deviation

Answer 33

σ

sqrt of n

Question 34

standard deviation of sampling distribution

Answer 34

sqrt( pq/n )

Question 35

confidence intervals

Answer 35

68-95-99

Question 36

confidence interval for a proportion

Answer 36

phat +/- z*sqrt( phat*qhat/n)

Question 37

confidence interval for µ

Answer 37

ybar +/- t_n-1 s/sqrt(n)

Question 38

sample size calculation

Answer 38

p(1-p)(z²/ME²)

Question 39

approximately standard normal

Answer 39

phat-p_o / sqrt( p_o(1-p_o)/n)

Question 40

test statistic for mean

Answer 40

ybar-µ_o / s/sqrt(n)

Question 41

test statistic for difference of means

Answer 41

dbar / (std dev/sqrt(n))

Question 42

sample size calculation

Answer 42

(z*s / ME)²

Question 43

confidence interval for difference of means

Answer 43

ybar₁-ybar₂ +/- t_df sqrt( s₁²/n₁ + s₂²/n₂)

Question 44

confidence interval for comparing two proportions

Answer 44

phat₁-phat₂ +/-

z * sqrt( (phat₁*qhat₁/n₁) + (phat₂*qhat₂/n₂)

Question 45

confidence interval for the regression slope

Answer 45

b₁ +/- t_n-2 * SE(b₁)

Question 46

test statistic for difference of two means

Answer 46

(ybar₁-ybar₂) / sqrt( s₁²/n₁ + s₂²/n₂)

Question 47

test statistic for comparing two proportions

Answer 47

phat₁-phat₂ / sqrt (phat1*qhat1/n1) + (phat2*qhat2/n2)

Question 48

pooled estimate of the proportion

Answer 48

y₁+y₂ / n₁+n₂

Question 49

test statistic for the regression slope

Answer 49

b₁-ß₁ / SE(b₁)

Question 50

test statistic for goodness of fit and homogeneity

Answer 50

Σ (obs-exp)² / exp

Question 51

degrees of freedom for goodness of fit and homogeneity

Answer 51

(#rows-1) * (#columns-1)

Question 52

z-scores for confidence intervals

Answer 52

1.645 1.96 2.576