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Finding the Fourth Proportional to 488.21, 728.77 and 420.17

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Solution

The fourth proportional to 488.21, 728.77 and 420.17 is: 627.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    488.21 : 728.77 = 420.17 : x
  2. Step 2: Convert to fraction form
    488.21/728.77 = 420.17/x
  3. Step 3: Cross multiply
    488.21x = 728.77 × 420.17
  4. Step 4: Simplify right side
    488.21x = 306,207.29
  5. Step 5: Solve for x
    x = 306,207.29/488.21
  6. Step 6: Final answer
    x = 627.20

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.