Unit 3 Topic 2 - Time Series Analysis

The trend of the amount of rainfall per week over a year in Western Queensland is probably

• Cyclic

• Seasonal

• Irregular

• There is no trend

The following figure shows the progressive maths test scores achieved by a Year 10 student over a 10-month period. What type of series is this?

• Cyclic

• Seasonal

• Irregular

• No Trend

A least-squares regression trend line was fitted to the data in the table.

Which of the following statements is NOT correct?

• The trend line is a poor match for the data.

• The gradient will be positive.

• There is a relatively steady increase over time.

• The value of the gradient is less than 10.

The following data represent the number of tomatoes canned in a day by Mary Farmer.

The data are smoothed using a 5-point moving average. The first two points in the smoothed trend line are

• 310 and 300

• 310 and 288

• 325 and 310

• 335 and 310

How many points would be obtained from the smoothed trend line

• 7

• 6

• 5

• 4

Which of the following is a false statement about seasonal indices?

• The sum of all indices equals number of seasons.

• A high index means a high season.

• Used for seasonal variations only.

• Can be negative or positive.

The following seasonal indices were obtained from a time series.

The value of the spring seasonal index is

• 1.18

• 0.94

• 1.08

• 1.06

A seasonally adjusted value for the autumn of 2018, when the original value was 520, is closest to

• 565

• 478

• 481

• 562

To deseasonalise data, _______ the relevant seasonal index.

• Multiply by

• Divide by

• Add

• Subtract

The value, after a 4-point moving average smoothing after centering, plotted against the year 2016 is

• 11.5

• 10.952

• 10.875

• 10.25