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Finding the Fourth Proportional to 101.80, 140.45 and 87.10

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Solution

The fourth proportional to 101.80, 140.45 and 87.10 is: 120.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.80 : 140.45 = 87.10 : x
  2. Step 2: Convert to fraction form
    101.80/140.45 = 87.10/x
  3. Step 3: Cross multiply
    101.80x = 140.45 × 87.10
  4. Step 4: Simplify right side
    101.80x = 12,233.20
  5. Step 5: Solve for x
    x = 12,233.20/101.80
  6. Step 6: Final answer
    x = 120.17

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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.