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Finding the Fourth Proportional to 71.82, 99.08 and 42.70

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Solution

The fourth proportional to 71.82, 99.08 and 42.70 is: 58.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.82 : 99.08 = 42.70 : x
  2. Step 2: Convert to fraction form
    71.82/99.08 = 42.70/x
  3. Step 3: Cross multiply
    71.82x = 99.08 × 42.70
  4. Step 4: Simplify right side
    71.82x = 4,230.72
  5. Step 5: Solve for x
    x = 4,230.72/71.82
  6. Step 6: Final answer
    x = 58.91

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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.