Mathematical Methods — Question 4

QCAA 2022, Paper 2 · 1 mark

Q4 · 2022 · Technology-activeSimple familiar1 mark

QUESTION 4

The distribution for a sample proportion

\hat p

has a mean of

0.15

and a standard deviation of

0.0345

. The sample size is

(A)

10

(B)

14

(C)

107

(D)

116

ABCD

WORKED SOLUTION

1 mark

ANSWER

C —

107

Worked solution

0.0345=\sqrt{0.15(0.85)/n}

, which gives

n\approx107

; C.

Selects option C.

[1 mark]

Worked explanation by QCE Vault; correct option verified against the QCAA answer key.