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Finding the Fourth Proportional to 420.47, 579.70 and 342.17

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Solution

The fourth proportional to 420.47, 579.70 and 342.17 is: 471.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.47 : 579.70 = 342.17 : x
  2. Step 2: Convert to fraction form
    420.47/579.70 = 342.17/x
  3. Step 3: Cross multiply
    420.47x = 579.70 × 342.17
  4. Step 4: Simplify right side
    420.47x = 198,355.65
  5. Step 5: Solve for x
    x = 198,355.65/420.47
  6. Step 6: Final answer
    x = 471.75

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.