aapl = load('aapl.txt'); please plot the price time series of all four stocks on the same figure and comment on whether you can observe the similarity from the plot easily in matlab

To plot time series data in MATLAB, we can use the built-in plot function.

Firstly, let us assume that the file aapl.txt contains time series data for Apple's stock prices. We can load the data into a variable aapl using the load command as follows:

main.m
aapl = load('aapl.txt');
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Assuming we have similar files msft.txt, goog.txt, and amzn.txt containing time series data for Microsoft, Google, and Amazon's stock prices respectively, we can load those into corresponding variables msft, goog, and amzn in a similar way.

main.m
msft = load('msft.txt');
goog = load('goog.txt');
amzn = load('amzn.txt');
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To plot the stock prices of all four companies on the same figure, we can use the hold on command after the first plot command. This will prevent MATLAB from clearing the figure every time we call plot.

main.m
plot(aapl);
hold on;
plot(msft);
plot(goog);
plot(amzn);
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After running this code, we should see a figure with four lines - one for each company's stock price data. We can add a legend to make it clear which line corresponds to which company's data:

main.m
legend('AAPL', 'MSFT', 'GOOG', 'AMZN');
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Whether or not we can observe similarities between the stock price data will depend on the magnitude of the differences between the data. If the differences are small, it may be difficult to observe similarities just by looking at the plot. However, if there are large similarities or differences, those will be easily observable on the plot.