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Finding the Fourth Proportional to 109.87, 151.61 and 66.20

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Solution

The fourth proportional to 109.87, 151.61 and 66.20 is: 91.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.87 : 151.61 = 66.20 : x
  2. Step 2: Convert to fraction form
    109.87/151.61 = 66.20/x
  3. Step 3: Cross multiply
    109.87x = 151.61 × 66.20
  4. Step 4: Simplify right side
    109.87x = 10,035.49
  5. Step 5: Solve for x
    x = 10,035.49/109.87
  6. Step 6: Final answer
    x = 91.34

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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.