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Finding the Fourth Proportional to 71.78, 99.02 and 42.66

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Solution

The fourth proportional to 71.78, 99.02 and 42.66 is: 58.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.78 : 99.02 = 42.66 : x
  2. Step 2: Convert to fraction form
    71.78/99.02 = 42.66/x
  3. Step 3: Cross multiply
    71.78x = 99.02 × 42.66
  4. Step 4: Simplify right side
    71.78x = 4,223.98
  5. Step 5: Solve for x
    x = 4,223.98/71.78
  6. Step 6: Final answer
    x = 58.85

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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.