# STA621 Assignment 1 Solution and Discussion

• Assignment No.1 (Course STA 621)
Fall 2019 (Total Marks 20)

17th November, 2019, Time 23:59
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Objective(s) of this Assignment:

The assignment is being uploaded to build up the concepts of Time Series.

Assignment # 1
Question 1: Marks: 5 +5=10
Part a
Why we calculate
i. Mean Percentage Error
ii. Mean Absolute Percentage Error

Part b
The following table shows the production of silver utensils (in thousands) at a certain factory in Islamabad.

Year 1970 1971 1972 1973 1974 1975 1976 1977
Utensils(000) 170.0 154.87 156.5 158.9 140.3 154.2 160.7 178.3

Calculate 3 year and 5 year single moving averages for the above time series data.

Question 2: Marks: 2x5 =10
The customer price index for medical care (medical cost) are given in the following table for the years 1980 to 1987.

Year t Production Xi Forecasted Fi
1980 106.0 107.09
1981 111.1 111.47
1982 117.2 115.85
1983 121.3 120.23
1984 125.2 124.61
1985 128.0 128.99
1986 132.6 133.37
1987 138.0 137.75
Total 979.4 979.36

Calculate

1. Mean error
2. Mean Absolute Error
3. Sum of Squared Error
4. Mean squared error
5. Standard Deviation of Error

1

4

2

1

36

3

3

15
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