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Finding the Fourth Proportional to 222.10, 306.50 and 128.85

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Solution

The fourth proportional to 222.10, 306.50 and 128.85 is: 177.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    222.10 : 306.50 = 128.85 : x
  2. Step 2: Convert to fraction form
    222.10/306.50 = 128.85/x
  3. Step 3: Cross multiply
    222.10x = 306.50 × 128.85
  4. Step 4: Simplify right side
    222.10x = 39,492.36
  5. Step 5: Solve for x
    x = 39,492.36/222.10
  6. Step 6: Final answer
    x = 177.82

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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.