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Finding the Fourth Proportional to 98.61, 136.09 and 57.18

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Solution

The fourth proportional to 98.61, 136.09 and 57.18 is: 78.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.61 : 136.09 = 57.18 : x
  2. Step 2: Convert to fraction form
    98.61/136.09 = 57.18/x
  3. Step 3: Cross multiply
    98.61x = 136.09 × 57.18
  4. Step 4: Simplify right side
    98.61x = 7,781.63
  5. Step 5: Solve for x
    x = 7,781.63/98.61
  6. Step 6: Final answer
    x = 78.91

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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.