Statistical inference — Question 2

QCAA 2024, Paper 2 · 1 mark

Q2 · 2024 · Technology-activeSimple familiar1 mark

QUESTION 2

Rounded to two decimal places, the

z

-value used in the calculation of an approximate 95% confidence interval for

\mu

(A)

0.95

(B)

1.64

(C)

1.96

(D)

2.58

ABCD

Question linkOriginal paper

WORKED SOLUTION

Answer C

1 mark

ANSWER

Worked solution

A two-sided 95% confidence interval leaves 2.5% in each tail of the standard normal distribution. The corresponding critical value is

z_{0.975}\approx1.96

Selects option C.

[1 mark]

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

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