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Finding the Fourth Proportional to 420.75, 580.47 and 310.49

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Solution

The fourth proportional to 420.75, 580.47 and 310.49 is: 428.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.75 : 580.47 = 310.49 : x
  2. Step 2: Convert to fraction form
    420.75/580.47 = 310.49/x
  3. Step 3: Cross multiply
    420.75x = 580.47 × 310.49
  4. Step 4: Simplify right side
    420.75x = 180,227.23
  5. Step 5: Solve for x
    x = 180,227.23/420.75
  6. Step 6: Final answer
    x = 428.35

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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.