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Finding the Fourth Proportional to 420.11, 578.40 and 346.30

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Solution

The fourth proportional to 420.11, 578.40 and 346.30 is: 476.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.11 : 578.40 = 346.30 : x
  2. Step 2: Convert to fraction form
    420.11/578.40 = 346.30/x
  3. Step 3: Cross multiply
    420.11x = 578.40 × 346.30
  4. Step 4: Simplify right side
    420.11x = 200,299.92
  5. Step 5: Solve for x
    x = 200,299.92/420.11
  6. Step 6: Final answer
    x = 476.78

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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.