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Finding the Fourth Proportional to 1,279.72, 1,920.19 and 663.31

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Solution

The fourth proportional to 1,279.72, 1,920.19 and 663.31 is: 995.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,279.72 : 1,920.19 = 663.31 : x
  2. Step 2: Convert to fraction form
    1,279.72/1,920.19 = 663.31/x
  3. Step 3: Cross multiply
    1,279.72x = 1,920.19 × 663.31
  4. Step 4: Simplify right side
    1,279.72x = 1,273,681.23
  5. Step 5: Solve for x
    x = 1,273,681.23/1,279.72
  6. Step 6: Final answer
    x = 995.28

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.