Given time series data x1, x2, . . . , xn, we shall find the moving averages from successive groups of k in the list. That is, we will find (x1 + x2 + . . . + xk) / k, then (x2 + x3 + . . . + xk+1) / k, . . . , up to (xnk+1 + xnk+2 + . . . + xn) / k. Moreover, we will plot these moving averages as a new time series.
Before executing the MOVEAVG program, we must enter the original time series into the calculator.
On the TI83, enter the time series into list L1.
On the TI86, enter the time series into list xStat.
On the TI89, enter the data points into column c1 in a Data Editor list called dist. (This list becomes the current list after executing many of the programs from this web site. Simply press APPS, then press 6, then press 1 to get to the current list.)
After the data is entered, execute the program by specifying the span k of the desired moving averages. The program then computes the successive moving averages and stores them in list L2 on the TI83, (or list yStat on the TI86, or column c2 in the current list on the TI89).
Upon completion, the program displays the mean, standard deviation, and range of the original time series, followed by the mean, standard deviation, and range of the created moving averages. The stat plot settings are also adjusted. To see a time plot of the moving averages, press GRAPH.
Example. Below (listed left to right) are the dollar gains of the NDX 100 over the S&P 500 for a period of 70 days. Create a list of the moving fiveday average gains over this time period.



















Solution. Enter the data (from left to right) into list L1 (xStat on the TI86, or column c1 on the TI89), then execute the MOVEAVG program with a span of 5. The output shows that the original data ranges from $748.4 to $657.6 with a mean of $22.84 and a standard deviation of $303.8, and that the new time series of 5day moving averages ranges from $374.52 to $418.32 with a mean of $28.32 and a standard deviation of $135.36.
After executing the program, press GRAPH to see a time plot of the moving averages, or view these values under list L2 (yStat on the TI86, or column c2 on the TI89).
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