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Finding the Fourth Proportional to 109.76, 151.62 and 87.90

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Solution

The fourth proportional to 109.76, 151.62 and 87.90 is: 121.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.76 : 151.62 = 87.90 : x
  2. Step 2: Convert to fraction form
    109.76/151.62 = 87.90/x
  3. Step 3: Cross multiply
    109.76x = 151.62 × 87.90
  4. Step 4: Simplify right side
    109.76x = 13,327.40
  5. Step 5: Solve for x
    x = 13,327.40/109.76
  6. Step 6: Final answer
    x = 121.42

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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.