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Finding the Fourth Proportional to 420.40, 580.12 and 243.33

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Solution

The fourth proportional to 420.40, 580.12 and 243.33 is: 335.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.40 : 580.12 = 243.33 : x
  2. Step 2: Convert to fraction form
    420.40/580.12 = 243.33/x
  3. Step 3: Cross multiply
    420.40x = 580.12 × 243.33
  4. Step 4: Simplify right side
    420.40x = 141,161.21
  5. Step 5: Solve for x
    x = 141,161.21/420.40
  6. Step 6: Final answer
    x = 335.78

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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.