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Finding the Fourth Proportional to 222.56, 307.12 and 129.28

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Solution

The fourth proportional to 222.56, 307.12 and 129.28 is: 178.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    222.56 : 307.12 = 129.28 : x
  2. Step 2: Convert to fraction form
    222.56/307.12 = 129.28/x
  3. Step 3: Cross multiply
    222.56x = 307.12 × 129.28
  4. Step 4: Simplify right side
    222.56x = 39,704.47
  5. Step 5: Solve for x
    x = 39,704.47/222.56
  6. Step 6: Final answer
    x = 178.40

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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.