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Finding the Fourth Proportional to 605.80, 908.70 and 420.20

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Solution

The fourth proportional to 605.80, 908.70 and 420.20 is: 630.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    605.80 : 908.70 = 420.20 : x
  2. Step 2: Convert to fraction form
    605.80/908.70 = 420.20/x
  3. Step 3: Cross multiply
    605.80x = 908.70 × 420.20
  4. Step 4: Simplify right side
    605.80x = 381,835.74
  5. Step 5: Solve for x
    x = 381,835.74/605.80
  6. Step 6: Final answer
    x = 630.30

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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.