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Finding the Fourth Proportional to 99.70, 137.46 and 85.12

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Solution

The fourth proportional to 99.70, 137.46 and 85.12 is: 117.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.70 : 137.46 = 85.12 : x
  2. Step 2: Convert to fraction form
    99.70/137.46 = 85.12/x
  3. Step 3: Cross multiply
    99.70x = 137.46 × 85.12
  4. Step 4: Simplify right side
    99.70x = 11,700.60
  5. Step 5: Solve for x
    x = 11,700.60/99.70
  6. Step 6: Final answer
    x = 117.36

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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.