Question:

If there is a very strong correlation between two variables then the correlationcoefficient must be

A.

any value larger than 1

B.

much smaller than 0, if the correlation is negative

C.

much larger than 0, regardless of whether the correlation is negative or positive

D.

none of these alternatives is correct

Answer» b. much smaller than 0, if the correlation is negative

Question:

The use of a smoothing technique is appropriate when

A.

random behaviour is the primary source of variation

B.

seasonality is present

C.

data exhibit a strong trend

D.

all of the above are correct

Answer» a. random behaviour is the primary source of variation

Question:

The sum of deviations about the arithmetic mean is always equal to _______

A.

1

B.

0

C.

variance

D.

geometric mean

Answer» b. 0

Question:

The time series component that indicates a steady increase or decrease over time isknown as a ____________

A.

order

B.

pattern

C.

trend

D.

seasonality

Answer» c. trend

Question:

Regressor refers to

A.

independent variable

B.

dependent variable

C.

error term

D.

dummy variable

Answer» a. independent variable

Question:

Which of the following is not a component of the multiplicative time series model?

A.

trend analysis

B.

seasonal variation

C.

cyclical variation

D.

regressive variation

Answer» d. regressive variation

Question:

If a value is missing in a time series we can do one of the following

A.

just copy the previous value

B.

estimate it as an average between two neighbouring values

C.

take the overall mean as the best estimate of it

D.

ignore it

Answer» b. estimate it as an average between two neighbouring values

Question:

Which of the following statements is not correct

A.

extreme value in data affects the mean

B.

mean is also known as average

C.

some data sets do not have mean

D.

at times weighted mean is much better than the simple mean

Answer» c. some data sets do not have mean