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Finding the Fourth Proportional to 385.60, 578.40 and 223.20

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Solution

The fourth proportional to 385.60, 578.40 and 223.20 is: 334.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.60 : 578.40 = 223.20 : x
  2. Step 2: Convert to fraction form
    385.60/578.40 = 223.20/x
  3. Step 3: Cross multiply
    385.60x = 578.40 × 223.20
  4. Step 4: Simplify right side
    385.60x = 129,098.88
  5. Step 5: Solve for x
    x = 129,098.88/385.60
  6. Step 6: Final answer
    x = 334.80

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.