WSC 12MAG: Unit 3 & 4 review

Bivariate data involves...

• two values

• two variables

• two data displays

• two data varieties

It is observed that as the number of hoodies sold each month increases, the number of beanies sold also increases. Which of these statements is true?

• There is a negative causation between the number of hoodies sold and the number of beanies sold each month

• There is a positive causation between the number of hoodies sold and the number of beanies sold each month

• There is a negative association between the number of hoodies sold and the number of beanies sold each month

• There is a positive association between the number of hoodies sold and the number of beanies sold each month

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

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• y = 16.79x - 1146.51

• y = 16.79x - 18.70

• y = 0.05x + 68.33

• y = 0.05x + 1.70

A confounding variable is one that...

• can only take on a certain number of values

• remains constant throughout a statistical investigation

• is used to predict a difference in the response variable

• other than the explanatory variable, influences the response variable

Calculate the fourth smoothed value for the 3-point moving average:

• 20

• 34

• 51.33

• 70.67

To deseasonalise a data point...

• divide by the seasonal index

• multiply by the seasonal index

• add the seasonal index

• subtract the seasonal index

If a data point has a seasonal index of 1.06, the deseasonalised data point will be...

• larger than the original data point, because the relevant season has average sales above the mean

• larger than the original data point, because the relevant season has average sales below the mean

• smaller than the original data point, because the relevant season has average sales above the mean

• smaller than the original data point, because the relevant season has average sales below the mean

Sales for a particular quarter were recorded as $7000. The seasonal index for this quarter is 0.92. Calculate the deseasonalised sales figure.

• $5924.80

• $6440.00

• $7608.70

• $8270.33

The first three terms in a sequence are 8, 14, and 20. What kind of sequence is this and why?

• Arithmetic, because it's going up

• Arithmetic, because the common difference is the same each time

• Geometric, because it's going up

• Geometric, because the common difference is the same each time