Question

The accompanying data file contains 20 observations for t and y_t.

t	1	2	3	4	5	6	7	8	9	10
yt	13.7	8.9	10.4	9.3	12.1	13.7	11.9	13.9	13.8	13.5
t	11	12	13	14	15	16	17	18	19	20
yt	10.8	10.6	12.3	9.3	11.2	10	10.5	13.7	10.3	10.7

The data are plotted below.

a. Discuss the presence of random variations.

• A. The smoother appearance of the graph suggests the presence of random variations.

• B. The smoother appearance of the graph suggests the absence of random variations.

• C. The jagged appearance of the graph suggests the presence of random variations.

• D. The jagged appearance of the graph suggests the absence of random variations.

b-1. Use the exponential smoothing method to make forecasts with α = 0.2. (Round intermediate calculations to at least 4 decimal places and final answers to 2 decimal places.)

t	yt	yˆt
1	13.7
2	8.9	____
3	10.4	____
⋮	⋮	⋮
19	10.3	____
20	10.7	____
21		____

b-2. Compute the resulting MSE and MAD. (Round intermediate calculations to at least 4 decimal places and final answers to 2 decimal places.)

MSE: ________
MAD: ________

c-1. Use the exponential smoothing method to make forecasts with α = 0.4. (Round intermediate calculations to at least 4 decimal places and final answers to 2 decimal places.)

t	yt	yˆty^t
1	13.7
2	8.9	____
3	10.4	____
⋮	⋮	⋮
19	10.3	____
20	10.7	____
21		____

c-2. Compute the resulting MSE and MAD. (Round intermediate calculations to at least 4 decimal places and final answers to 2 decimal places.)

MSE: ________
MAD: ________

d. Use the appropriate value of α to make a forecast for period 21. (Round intermediate calculations to at least 4 decimal places and final answer to 2 decimal places.)

yˆt: ______________

Answer 1

Answer:---                                                       Date:--14/07/2019

a The jagged appearance of the graph suggests the presence of random variations.