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Finding the Fourth Proportional to 420.60, 580.71 and 310.20

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Solution

The fourth proportional to 420.60, 580.71 and 310.20 is: 428.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.60 : 580.71 = 310.20 : x
  2. Step 2: Convert to fraction form
    420.60/580.71 = 310.20/x
  3. Step 3: Cross multiply
    420.60x = 580.71 × 310.20
  4. Step 4: Simplify right side
    420.60x = 180,136.24
  5. Step 5: Solve for x
    x = 180,136.24/420.60
  6. Step 6: Final answer
    x = 428.28

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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.