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Finding the Fourth Proportional to 221.60, 305.83 and 128.35

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Solution

The fourth proportional to 221.60, 305.83 and 128.35 is: 177.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.60 : 305.83 = 128.35 : x
  2. Step 2: Convert to fraction form
    221.60/305.83 = 128.35/x
  3. Step 3: Cross multiply
    221.60x = 305.83 × 128.35
  4. Step 4: Simplify right side
    221.60x = 39,253.10
  5. Step 5: Solve for x
    x = 39,253.10/221.60
  6. Step 6: Final answer
    x = 177.13

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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.