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Finding the Fourth Proportional to 1,308.78, 1,963.32 and 431.10

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Solution

The fourth proportional to 1,308.78, 1,963.32 and 431.10 is: 646.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,308.78 : 1,963.32 = 431.10 : x
  2. Step 2: Convert to fraction form
    1,308.78/1,963.32 = 431.10/x
  3. Step 3: Cross multiply
    1,308.78x = 1,963.32 × 431.10
  4. Step 4: Simplify right side
    1,308.78x = 846,387.25
  5. Step 5: Solve for x
    x = 846,387.25/1,308.78
  6. Step 6: Final answer
    x = 646.70

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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.