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Finding the Fourth Proportional to 140.10, 209.78 and 75.78

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Solution

The fourth proportional to 140.10, 209.78 and 75.78 is: 113.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.10 : 209.78 = 75.78 : x
  2. Step 2: Convert to fraction form
    140.10/209.78 = 75.78/x
  3. Step 3: Cross multiply
    140.10x = 209.78 × 75.78
  4. Step 4: Simplify right side
    140.10x = 15,897.13
  5. Step 5: Solve for x
    x = 15,897.13/140.10
  6. Step 6: Final answer
    x = 113.47

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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.