# Calculations?

• Jan 29th 2008, 02:47 AM
cu4mail
Calculations?
The following table shows the number of items of certain product imported into the United Kingdom is given below in thousands of units for the Years
1955-64.

Years 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964
Consumption 170 210 188 98 83 131 205 182 90 92
of Cotton
(Thousands of bales).

Calculate
i) 5-years moving total
ii) 5-years moving average.
All calculations should be in Excel.

Thanks
• Jan 29th 2008, 06:12 AM
colby2152
Quote:

Originally Posted by cu4mail
The following table shows the number of items of certain product imported into the United Kingdom is given below in thousands of units for the Years
1955-64.

Years 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964
Consumption 170 210 188 98 83 131 205 182 90 92
of Cotton
(Thousands of bales).

Calculate
i) 5-years moving total
ii) 5-years moving average.
All calculations should be in Excel.

Thanks

Excel automatically compiles these results for you by graphing it. However, please note that a simple moving average (SMA) is the unweighted mean of the previous n data points. Therefore, you calculate the mean of the last five years of data for each point. Likewise, you sum the values of the last five years for the moving total.
• Jan 29th 2008, 07:37 AM
CaptainBlack
Quote:

Originally Posted by colby2152
Excel automatically compiles these results for you by graphing it. However, please note that a simple moving average (SMA) is the unweighted mean of the previous n data points. Therefore, you calculate the mean of the last five years of data for each point. Likewise, you sum the values of the last five years for the moving total.

I would have put the five year moving avaerage for year $n$ tobe:

$(x_{n-2}+x_{n-1}+x_n+x_{n+1}+x_{n+2})/5$

that is I would always prefer the central moving average.

(of course Excel just gives the rolling MA)

RonL
• Jan 29th 2008, 07:40 AM
colby2152
Quote:

Originally Posted by CaptainBlack
I would have put the five year moving avaerage for year $n$ tobe:

$(x_{n-2}+x_{n-1}+x_n+x_{n+1}+x_{n+2})/5$

RonL

It depends where it is centered around. Simple moving averages look at past data, because that data is given and known. You cannot use unknown values in the future for a moving average.