EXAM 1

Question 1

σ

Answer 1

standard deviation/ population standard deviation

Question 2

µ

Answer 2

mean/ population mean

Question 3

σ²

Answer 3

variance/ population variance

Question 4

z to find z-score for standard normal

Answer 4

z= (x-µ)/σ

Question 5

Formula to find z when area between +- Z is given

Answer 5

z= (1- area) /2

Question 6

N

Answer 6

population size

Question 7

n

Answer 7

sample size

Question 8

p

Answer 8

population proportion

Question 9

p̅

Answer 9

sample proportion

Question 10

x̅

Answer 10

sample mean

Question 11

s²

Answer 11

sample variance

Question 12

s

Answer 12

sample standard deviation

Question 13

converting to standard normal mean

Answer 13

z= (x̅ - µ)/(σ ÷ √n )

Question 14

point estimator of µ

Answer 14

x̅

Question 15

point estimator of s²

Answer 15

σ²

Question 16

point estimator of p̅

Answer 16

p

Question 17

sample proportion p̅ formula

Answer 17

p̅ = x /n

Question 18

sample mean x̅ formula

Answer 18

x̅ = Σ x_i / n

Question 19

sample variance s² formula

Answer 19

s² = Σ (xi - x̅)2 / n - 1

Question 20

standard deviation of p̅ / standard error of p̅

Answer 20

σ_p̅ = √ p(1 - p)/n

Question 21

z of p̅ formula

Answer 21

z = (p̅ - p) ÷ σ_p̅​

Question 22

formula for s (sample standard deviation)

Answer 22

s = (x̅ - µ) /z

or

s = σ/ √n

or

s= √(Σ (x_i - x̅)²) / n - 1

Question 23

Confidence Interval for known σ

Answer 23

CI = x̅ ± z_α​/2 * σ​/√​n

Question 24

Confidence Interval unknown σ

Answer 24

CI = x̅ ± t_α​/2 * s​/√​n

Question 25

E (desired Margin of Error)

Answer 25

E = z_α​/2 \* σ​/√​n

Question 26

Range Rule

Answer 26

Range Rule = Range/4

Question 27

Sample Size for µ (pop. mean) interval estimate.

Answer 27

n = (z_α/2)² \* σ²/E²

Question 28

Interval estimate for p̅

Answer 28

p̅ CI = p̅ ± z_α/2 √ p̅(1 - p̅)/n

Question 29

Margin of Error p̅

Answer 29

z_α/2 √ p̅(1 - p̅)/n