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Finding the Fourth Proportional to 140.55, 210.85 and 86.34

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Solution

The fourth proportional to 140.55, 210.85 and 86.34 is: 129.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.55 : 210.85 = 86.34 : x
  2. Step 2: Convert to fraction form
    140.55/210.85 = 86.34/x
  3. Step 3: Cross multiply
    140.55x = 210.85 × 86.34
  4. Step 4: Simplify right side
    140.55x = 18,204.79
  5. Step 5: Solve for x
    x = 18,204.79/140.55
  6. Step 6: Final answer
    x = 129.53

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.