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Finding the Fourth Proportional to 420.52, 580.26 and 309.88

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Solution

The fourth proportional to 420.52, 580.26 and 309.88 is: 427.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.52 : 580.26 = 309.88 : x
  2. Step 2: Convert to fraction form
    420.52/580.26 = 309.88/x
  3. Step 3: Cross multiply
    420.52x = 580.26 × 309.88
  4. Step 4: Simplify right side
    420.52x = 179,810.97
  5. Step 5: Solve for x
    x = 179,810.97/420.52
  6. Step 6: Final answer
    x = 427.59

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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.