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Finding the Fourth Proportional to 140.31, 210.51 and 71.85

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Solution

The fourth proportional to 140.31, 210.51 and 71.85 is: 107.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.31 : 210.51 = 71.85 : x
  2. Step 2: Convert to fraction form
    140.31/210.51 = 71.85/x
  3. Step 3: Cross multiply
    140.31x = 210.51 × 71.85
  4. Step 4: Simplify right side
    140.31x = 15,125.14
  5. Step 5: Solve for x
    x = 15,125.14/140.31
  6. Step 6: Final answer
    x = 107.80

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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.