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Finding the Fourth Proportional to 398.64, 550.14 and 221.60

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Solution

The fourth proportional to 398.64, 550.14 and 221.60 is: 305.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.64 : 550.14 = 221.60 : x
  2. Step 2: Convert to fraction form
    398.64/550.14 = 221.60/x
  3. Step 3: Cross multiply
    398.64x = 550.14 × 221.60
  4. Step 4: Simplify right side
    398.64x = 121,911.02
  5. Step 5: Solve for x
    x = 121,911.02/398.64
  6. Step 6: Final answer
    x = 305.82

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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.