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Finding the Fourth Proportional to 99.40, 138.12 and 98.24

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Solution

The fourth proportional to 99.40, 138.12 and 98.24 is: 136.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.40 : 138.12 = 98.24 : x
  2. Step 2: Convert to fraction form
    99.40/138.12 = 98.24/x
  3. Step 3: Cross multiply
    99.40x = 138.12 × 98.24
  4. Step 4: Simplify right side
    99.40x = 13,568.91
  5. Step 5: Solve for x
    x = 13,568.91/99.40
  6. Step 6: Final answer
    x = 136.51

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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.