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Finding the Fourth Proportional to 101.57, 140.05 and 86.79

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Solution

The fourth proportional to 101.57, 140.05 and 86.79 is: 119.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.57 : 140.05 = 86.79 : x
  2. Step 2: Convert to fraction form
    101.57/140.05 = 86.79/x
  3. Step 3: Cross multiply
    101.57x = 140.05 × 86.79
  4. Step 4: Simplify right side
    101.57x = 12,154.94
  5. Step 5: Solve for x
    x = 12,154.94/101.57
  6. Step 6: Final answer
    x = 119.67

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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.