Melanie, Morgan, and Joel decided to start a web design company and made investments in the ratio of 3 : 4 : 4, respectively. After one year, if Melanie increased her initial investment by 50%, Morgan decreased her initial investment of $7,000 by 25%, and Joel did not change his investment, find the new ratio of their investment, reduced to the lowest terms. (Question relates to Mathematics of Business and Finance in Ratios, Proportions and Applications).

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Express in lowest terms