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Finding the Fourth Proportional to 99.88, 138.47 and 97.90

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Solution

The fourth proportional to 99.88, 138.47 and 97.90 is: 135.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.88 : 138.47 = 97.90 : x
  2. Step 2: Convert to fraction form
    99.88/138.47 = 97.90/x
  3. Step 3: Cross multiply
    99.88x = 138.47 × 97.90
  4. Step 4: Simplify right side
    99.88x = 13,556.21
  5. Step 5: Solve for x
    x = 13,556.21/99.88
  6. Step 6: Final answer
    x = 135.73

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.