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Finding the Fourth Proportional to 1,013.50, 1,398.30 and 640.87

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Solution

The fourth proportional to 1,013.50, 1,398.30 and 640.87 is: 884.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,013.50 : 1,398.30 = 640.87 : x
  2. Step 2: Convert to fraction form
    1,013.50/1,398.30 = 640.87/x
  3. Step 3: Cross multiply
    1,013.50x = 1,398.30 × 640.87
  4. Step 4: Simplify right side
    1,013.50x = 896,128.52
  5. Step 5: Solve for x
    x = 896,128.52/1,013.50
  6. Step 6: Final answer
    x = 884.19

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.