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Finding the Fourth Proportional to 109.20, 150.56 and 87.40

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Solution

The fourth proportional to 109.20, 150.56 and 87.40 is: 120.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.20 : 150.56 = 87.40 : x
  2. Step 2: Convert to fraction form
    109.20/150.56 = 87.40/x
  3. Step 3: Cross multiply
    109.20x = 150.56 × 87.40
  4. Step 4: Simplify right side
    109.20x = 13,158.94
  5. Step 5: Solve for x
    x = 13,158.94/109.20
  6. Step 6: Final answer
    x = 120.50

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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.