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Finding the Fourth Proportional to 102.32, 140.75 and 85.71

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Solution

The fourth proportional to 102.32, 140.75 and 85.71 is: 117.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.32 : 140.75 = 85.71 : x
  2. Step 2: Convert to fraction form
    102.32/140.75 = 85.71/x
  3. Step 3: Cross multiply
    102.32x = 140.75 × 85.71
  4. Step 4: Simplify right side
    102.32x = 12,064.10
  5. Step 5: Solve for x
    x = 12,064.10/102.32
  6. Step 6: Final answer
    x = 117.91

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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.