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Finding the Fourth Proportional to 385.54, 578.72 and 221.63

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Solution

The fourth proportional to 385.54, 578.72 and 221.63 is: 332.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.54 : 578.72 = 221.63 : x
  2. Step 2: Convert to fraction form
    385.54/578.72 = 221.63/x
  3. Step 3: Cross multiply
    385.54x = 578.72 × 221.63
  4. Step 4: Simplify right side
    385.54x = 128,259.37
  5. Step 5: Solve for x
    x = 128,259.37/385.54
  6. Step 6: Final answer
    x = 332.68

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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.