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Finding the Fourth Proportional to 420.32, 578.48 and 355.68

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Solution

The fourth proportional to 420.32, 578.48 and 355.68 is: 489.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.32 : 578.48 = 355.68 : x
  2. Step 2: Convert to fraction form
    420.32/578.48 = 355.68/x
  3. Step 3: Cross multiply
    420.32x = 578.48 × 355.68
  4. Step 4: Simplify right side
    420.32x = 205,753.77
  5. Step 5: Solve for x
    x = 205,753.77/420.32
  6. Step 6: Final answer
    x = 489.52

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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.