Additional notes

Question 1

Approximations

Answer 1

Binomial to normal
np > 5 and nq > 5

Binomial to poisson
n > 50 and np < 5

Poisson to normal
mean > 15

Question 2

Continuity correction

Answer 2

used when approximating binomial or poisson to normal

Question 3

Combined standard deviation and variance

Answer 3

Sd: square standard deviation and multiply by constant, or calculate combined variance then square root value
Var: sqaure constant and add variance

Question 4

Confidence interval width

Answer 4

2(z(σ/√n)) = confidence interval width

Question 5

PDF

Answer 5

area = 1
f(x) ≥ 0