Daily high temperatures in St. Louis for the last week were as follows: 95, 92, 93, 92, 95, 90, 90 (yesterday). a) The high temperature for today using a 3-day moving average = 91.7 degrees (round your response to one decimal place). b) The high temperature for today using a 2-day moving average = 90 degrees (round your response to one decimal place). c) The mean absolute deviation based on a 2-day moving average = 1.9 degrees (round your response to one decimal place). d) The mean squared error for the 2-day moving average = nothing degrees squared (round your response to one decimal place).

a) T = 91.7 degrees

b) T = 90 degrees

c) MAD = 1.9

d) MSE = 5.05

Step-by-step explanation:

Given:

- Daily high temperatures in St. Louis for the last week were as follows:

                                   95, 92, 93, 92, 95, 90, 90

Find:

a) Forecast the high temperature today, using a 3-day moving average.

b) Forecast the high temperature today, using a 2-day moving average.

c) Calculate the mean absolute deviation based on a 2-day moving average, covering all days in which you can have a forecast and an actual temperature.

d) The mean squared error for the 2-day moving average

Solution:

a)

- The set of 3 day moving average is as follows:

4.   (95 + 92 + 93) ÷ 3 = 93.33⁰C

5.  (92 + 93 + 92) ÷ 3 = 92.33⁰C

6.  (93 + 92 + 95) ÷ 3 = 93.33⁰C

7.  (92 + 95 + 90) ÷ 3 = 92.33⁰C

8.  (95 + 90 + 90) ÷ 3 = 91.667⁰C

- Now use these points on excel sheet to forecast the temperature for today. The line of best fit is given:

T = 91.7 degrees

b)

- The set of 2 day moving average is as follows:

3.   (95 + 92) ÷ 2 = 93.5⁰C

4.  (95 + 93) ÷ 2 = 92.5⁰C

5.  (93 + 92) ÷ 2 = 92.5⁰C

6.  (92 + 95) ÷ 2 = 93.5⁰C

7.  (95 + 90) ÷ 2 = 92.5⁰C

8. (90 + 90) ÷ 2 = 90⁰C

- Now use these points on excel sheet to forecast the temperature for today. The line of best fit is given:

T = 90 degrees

c)

                             Error             Error^2

3.   93.5⁰C            0.5                  0.25

4.   92.5⁰C            0.5                  0.25

5.   92.5⁰C            2.5                  6.25

6.   93.5⁰C            3.5                  12.25

7.   92.5⁰C            2.5                  6.25

8.   90⁰C

- The mean absolute deviation as follows:

                              MAD = Sum of all errors  / 5

                              MAD = (0.5+0.5+2.5+3.5+2.5)  / 5

                              MAD = 1.9

d)

- The mean squared error deviation as follows:

                              MSE = Sum of all error^2  / 5

                              MSE = (0.25+0.25+6.25+12.25+6.25)  / 5

                              MSE = 5.05