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Finding the Fourth Proportional to 99.79, 137.70 and 68.76

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Solution

The fourth proportional to 99.79, 137.70 and 68.76 is: 94.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.79 : 137.70 = 68.76 : x
  2. Step 2: Convert to fraction form
    99.79/137.70 = 68.76/x
  3. Step 3: Cross multiply
    99.79x = 137.70 × 68.76
  4. Step 4: Simplify right side
    99.79x = 9,468.25
  5. Step 5: Solve for x
    x = 9,468.25/99.79
  6. Step 6: Final answer
    x = 94.88

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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.