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Finding the Fourth Proportional to 140.76, 208.80 and 138.60

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Solution

The fourth proportional to 140.76, 208.80 and 138.60 is: 205.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.76 : 208.80 = 138.60 : x
  2. Step 2: Convert to fraction form
    140.76/208.80 = 138.60/x
  3. Step 3: Cross multiply
    140.76x = 208.80 × 138.60
  4. Step 4: Simplify right side
    140.76x = 28,939.68
  5. Step 5: Solve for x
    x = 28,939.68/140.76
  6. Step 6: Final answer
    x = 205.60

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Why These Related Problems?

These problems maintain the same ratio (1.48) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.