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Finding the Fourth Proportional to 420.20, 580.16 and 315.52

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Solution

The fourth proportional to 420.20, 580.16 and 315.52 is: 435.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.20 : 580.16 = 315.52 : x
  2. Step 2: Convert to fraction form
    420.20/580.16 = 315.52/x
  3. Step 3: Cross multiply
    420.20x = 580.16 × 315.52
  4. Step 4: Simplify right side
    420.20x = 183,052.08
  5. Step 5: Solve for x
    x = 183,052.08/420.20
  6. Step 6: Final answer
    x = 435.63

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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.