The quarterly sales data (number of copies sold) for a college textbook over the past three years follow. Quarter Year 1 Year 2 Year 3 1 1,690 1,800 1,860 2 950 910 1,110 3 2,625 2,910 2,940 4 2,510 2,370 2,615 (a) Construct a time series plot. What type of pattern exists in the data? There appears be a downward linear trend but no seasonal pattern in the data.There appears to be a seasonal pattern in the data and perhaps a moderate upward linear trend. There appears be an upward linear trend but no seasonal pattern in the data.There appears to be a seasonal pattern in the data and perhaps a moderate downward linear trend. (b) Use a regression model with dummy variables as follows to develop an equation to account for seasonal effects in the data. (Round your numerical values to the nearest integer.) Qrt1 = 1 if quarter 1, 0 otherwise; Qrt2 = 1 if quarter 2, 0 otherwise; Qrt3 = 1 if quarter 3, 0 otherwise t = (c) Using the equation developed in part (b), compute the quarterly forecasts for year 4. (Round your answers to the nearest ten.) quarter 1 forecastquarter 2 forecastquarter 3 forecastquarter 4 forecast (d) Let t = 1 refer to the observation in Quarter 1 of Year 1; let t = 2 refer to the observation in Quarter 2 of Year 1; and t = 12 to refer to the observation in Quarter 4 of Year 3. Using the dummy variables defined in part (b) and also using t, develop an equation to account for seasonal effects and any linear trend in the time series. (Round your numerical values to the nearest integer.) t =

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Related questions

Question

A statistical program is recommended.

The quarterly sales data (number of copies sold) for a college textbook over the past three years follow.

Quarter	Year 1	Year 2	Year 3
1	1,690	1,800	1,860
2	950	910	1,110
3	2,625	2,910	2,940
4	2,510	2,370	2,615

(a)

Construct a time series plot.

What type of pattern exists in the data?

There appears be a downward linear trend but no seasonal pattern in the data.There appears to be a seasonal pattern in the data and perhaps a moderate upward linear trend. There appears be an upward linear trend but no seasonal pattern in the data.There appears to be a seasonal pattern in the data and perhaps a moderate downward linear trend.

(b)

Use a regression model with dummy variables as follows to develop an equation to account for seasonal effects in the data. (Round your numerical values to the nearest integer.)

Qrt1 = 1 if quarter 1, 0 otherwise; Qrt2 = 1 if quarter 2, 0 otherwise; Qrt3 = 1 if quarter 3, 0 otherwise

_t =

(c)

Using the equation developed in part (b), compute the quarterly forecasts for year 4. (Round your answers to the nearest ten.)

quarter 1 forecastquarter 2 forecastquarter 3 forecastquarter 4 forecast

(d)

Let

t = 1

refer to the observation in Quarter 1 of Year 1; let

t = 2

refer to the observation in Quarter 2 of Year 1;

and

t = 12

to refer to the observation in Quarter 4 of Year 3. Using the dummy variables defined in part (b) and also using t, develop an equation to account for seasonal effects and any linear trend in the time series. (Round your numerical values to the nearest integer.)

_t =

Based upon the seasonal effects in the data and linear trend, compute the quarterly forecasts for year 4. (Round your answers to the nearest ten.)

quarter 1 forecastquarter 2 forecastquarter 3 forecastquarter 4 forecast

Expert Solution

Trending now

This is a popular solution!

Step by step

Solved in 5 steps with 3 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

$Data mining$

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.

Similar questions