2020 Multiple Choice QCAA

Four linear models have been developed for a data set. Identify the residual plot that indicates that the developed linear model is justified.

• A

• B

• C

• D

The standard Australian time zones are shown on the map.

All states and territories, except Western Australia (WA), Queensland (QLD) and the Northern Territory (NT), have daylight saving in summer. Daylight saving time is 1 hour ahead of standard time. When it is 10:00 am daylight saving time in New South Wales (NSW), it is

• (A) 9:30 am in South Australia (SA) and 9:00 am in QLD.

• (B) 9:30 am in SA and 11:00 am in QLD.

• (C) 10:30 am in SA and 9:00 am in QLD.

• (D) 10:30 am in SA and 11:00 am in QLD.

For the sequence 4, 2, 0, –2, –4 … the common difference is

• (A) 4

• (B) 2

• (C) –2

• (D) –4

Which of the following graphs could be modelled using a geometric sequence?

• A

• B

• C

• D

• (A) y = 16.79x - 1146.51

• (B) y = 16.79x - 18.70

• (C) y = 0.05x + 68.33

• (D) y = 0.05x +1.70

A loan of $10 000 has interest charged on a reducing balance at 6% p.a. compounding quarterly with quarterly repayments of $700. The balance after 6 months is

• (A) $8696.75

• (B) $8891.75

• (C) $8900.00

• (D) $9794.00

What is the length of the minimum spanning tree for this network? All distances are in kilometres (km).

• (A) 22 km

• (B) 14 km

• (C) 12 km

• (D) 3 km

The following scatterplot shows a linear association between two numerical variables.

Choose the best description for the direction and strength of the association.

• (A) strong positive

• (B) strong negative

• (C) weak positive

• (D) weak negative

It is observed that as the number of ice blocks sold each month increases, the number of fans sold also increases. Which of these statements is therefore true?

• (A) There is a negative causation between the number of ice blocks sold and the number of fans sold each month.

• (B) There is a positive causation between the number of ice blocks sold and the number of fans sold each month.

• (C) There is a negative association between the number of ice blocks sold and the number of fans sold each month.

• (D) There is a positive association between the number of ice blocks sold and the number of fans sold each month.

Which of the following graphs represents a time series plot with a three-point moving average?

• A

• B

• C

• D