The file DJIA.csv on the booksite contains all closing stock prices in the history of the Dow Jones Industrial Average, in the comma-separatedvalue format. Create a data type DowJonesEntry that can hold one entry in the table, with values for date, opening price, daily high, daily low, closing price, and so forth. Then, create a data type DowJones that reads the file to build an array of DowJonesEntry objects and supports methods for computing averages over various periods of time. Finally, create interesting DowJones clients to produce plots of the data. Be creative: this path is well trodden.