Question 1

A least-squares regression line for the annual profit trend of a small restaurant is calculated as being t = 35983 + 3567x. Estimate the time point value for year 6.

Accepted Answer

A)  £57385 
B)  £53818 
C)  £60952 
D)  £64519 
A)  £57385 
B)  £53818 
C)  £60952 
D)  £64519 A

Question 2

Which of the following options is NOT a way to extract a trend from time series values?

Accepted Answer

A)  Least-squares regression 
B)  Moving averages 
C)  Semi-averages 
D)  Floating averages 
A)  Least-squares regression 
B)  Moving averages 
C)  Semi-averages 
D)  Floating averages D

Question 3

When calculating a moving average of a data set with a natural cycle of 6 months, what should be the length of the period?

Accepted Answer

A)  4 
B)  12 
C)  6 
D)  2 
A)  4 
B)  12 
C)  6 
D)  2 C

Question 4

Data for the number of containers unloaded at the Port of Shanghai is collected every day. Values for the last 7 days are to be used as the upper group in a semi-average calculation. Work out the average (mean) for this group (1 decimal place): 85,235; 92,467; 63,287; 95,402; 86,263; 74,224; 89,123

Accepted Answer

A)  83714.4 
B)  83714.5 
C)  83714.0 
D)  83714.3 
A)  83714.4 
B)  83714.5 
C)  83714.0 
D)  83714.3

Question 5

What technique is used to place moving average values when the length of the period is even?

Accepted Answer

A)  Fixing 
B)  Averaging 
C)  Splitting 
D)  Centering 
A)  Fixing 
B)  Averaging 
C)  Splitting 
D)  Centering

Question 6

Which of the following statements concerning the moving average method of calculating a trend is NOT true?

Accepted Answer

A)  The number of values used to calculate the moving average is called the period 
B)  Values should be chosen so that numbers used to calculate the moving average do not overlap 
C)  The number of values used to calculate the moving average should always be the same 
D)  There will always be a smaller number of moving average values than original data points 
A)  The number of values used to calculate the moving average is called the period 
B)  Values should be chosen so that numbers used to calculate the moving average do not overlap 
C)  The number of values used to calculate the moving average should always be the same 
D)  There will always be a smaller number of moving average values than original data points

Question 7

Which statement concerning the semi-averages method is NOT correct?

Accepted Answer

A)  Both the lower and upper groups should have the same number of data points 
B)  Mean values for the lower and upper groups are plotted against the median value of the group 
C)  Data should be arranged in order of size from smallest to largest data point 
D)  If the data set contains an odd number of points the middle point should be ignored 
A)  Both the lower and upper groups should have the same number of data points 
B)  Mean values for the lower and upper groups are plotted against the median value of the group 
C)  Data should be arranged in order of size from smallest to largest data point 
D)  If the data set contains an odd number of points the middle point should be ignored

Question 8

When analysing a data set of 35 points, with a period length of 7, how many moving average values will be generated?

Accepted Answer

A)  35 
B)  33 
C)  31 
D)  29 
A)  35 
B)  33 
C)  31 
D)  29

Question 9

Which of these statements concerning the choice of technique for extracting the trend is NOT correct?

Accepted Answer

A)  The moving average method is disadvantaged by not having values for the start and end data points 
B)  The least squares regression method is suitable for use with highly seasonal data 
C)  Semi-average and least squares regression techniques always result in a straight-line trend 
D)  The moving average method is able to show the true nature of the trend in the data 
A)  The moving average method is disadvantaged by not having values for the start and end data points 
B)  The least squares regression method is suitable for use with highly seasonal data 
C)  Semi-average and least squares regression techniques always result in a straight-line trend 
D)  The moving average method is able to show the true nature of the trend in the data

Question 10

Which of the following statements about time series trends IS true?

Accepted Answer

A)  A time series can always be expressed as a straight line 
B)  A time series comprises, trend, seasonal and residual components 
C)  The trend component of a time series may fluctuate in a cyclical fashion 
D)  A trend should always show an increase over time 
A)  A time series can always be expressed as a straight line 
B)  A time series comprises, trend, seasonal and residual components 
C)  The trend component of a time series may fluctuate in a cyclical fashion 
D)  A trend should always show an increase over time

Exam 16: Time Series Trend

A least-squares regression line for the annual profit trend of a small restaurant is calculated as being t = 35983 + 3567x. Estimate the time point value for year 6.

Which of the following options is NOT a way to extract a trend from time series values?

When calculating a moving average of a data set with a natural cycle of 6 months, what should be the length of the period?

Data for the number of containers unloaded at the Port of Shanghai is collected every day. Values for the last 7 days are to be used as the upper group in a semi-average calculation. Work out the average (mean) for this group (1 decimal place): 85,235; 92,467; 63,287; 95,402; 86,263; 74,224; 89,123

What technique is used to place moving average values when the length of the period is even?

Which of the following statements concerning the moving average method of calculating a trend is NOT true?

Which statement concerning the semi-averages method is NOT correct?

When analysing a data set of 35 points, with a period length of 7, how many moving average values will be generated?

Which of these statements concerning the choice of technique for extracting the trend is NOT correct?

Which of the following statements about time series trends IS true?

Introduction to Business Mathematics and Statistics

Sampling and Data Collection

Data and Their Accuracy

Frequency Distributions and Charts

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Arithmetic Mean

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Special Published Indices

Interest and Depreciation

Present Value and Investment Appraisal

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Linear Equations

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Differentiation and Integration

Cost, Revenue and Profit Functions

Set Theory and Enumeration

Introduction to Probability

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