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Finding the Fourth Proportional to 670.66, 1,005.12 and 486.20

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Solution

The fourth proportional to 670.66, 1,005.12 and 486.20 is: 728.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.66 : 1,005.12 = 486.20 : x
  2. Step 2: Convert to fraction form
    670.66/1,005.12 = 486.20/x
  3. Step 3: Cross multiply
    670.66x = 1,005.12 × 486.20
  4. Step 4: Simplify right side
    670.66x = 488,691.86
  5. Step 5: Solve for x
    x = 488,691.86/670.66
  6. Step 6: Final answer
    x = 728.68

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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.