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Finding the Fourth Proportional to 653.60, 978.60 and 508.40

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Solution

The fourth proportional to 653.60, 978.60 and 508.40 is: 761.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    653.60 : 978.60 = 508.40 : x
  2. Step 2: Convert to fraction form
    653.60/978.60 = 508.40/x
  3. Step 3: Cross multiply
    653.60x = 978.60 × 508.40
  4. Step 4: Simplify right side
    653.60x = 497,520.24
  5. Step 5: Solve for x
    x = 497,520.24/653.60
  6. Step 6: Final answer
    x = 761.20

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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.