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Finding the Fourth Proportional to 649.60, 972.48 and 406.40

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Solution

The fourth proportional to 649.60, 972.48 and 406.40 is: 608.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.60 : 972.48 = 406.40 : x
  2. Step 2: Convert to fraction form
    649.60/972.48 = 406.40/x
  3. Step 3: Cross multiply
    649.60x = 972.48 × 406.40
  4. Step 4: Simplify right side
    649.60x = 395,215.87
  5. Step 5: Solve for x
    x = 395,215.87/649.60
  6. Step 6: Final answer
    x = 608.40

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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.