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Finding the Fourth Proportional to 123.31, 170.05 and 98.70

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Solution

The fourth proportional to 123.31, 170.05 and 98.70 is: 136.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.31 : 170.05 = 98.70 : x
  2. Step 2: Convert to fraction form
    123.31/170.05 = 98.70/x
  3. Step 3: Cross multiply
    123.31x = 170.05 × 98.70
  4. Step 4: Simplify right side
    123.31x = 16,783.94
  5. Step 5: Solve for x
    x = 16,783.94/123.31
  6. Step 6: Final answer
    x = 136.11

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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.