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Finding the Fourth Proportional to 420.56, 580.32 and 289.32

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Solution

The fourth proportional to 420.56, 580.32 and 289.32 is: 399.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.56 : 580.32 = 289.32 : x
  2. Step 2: Convert to fraction form
    420.56/580.32 = 289.32/x
  3. Step 3: Cross multiply
    420.56x = 580.32 × 289.32
  4. Step 4: Simplify right side
    420.56x = 167,898.18
  5. Step 5: Solve for x
    x = 167,898.18/420.56
  6. Step 6: Final answer
    x = 399.23

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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.