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Finding the Fourth Proportional to 109.80, 151.68 and 87.74

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Solution

The fourth proportional to 109.80, 151.68 and 87.74 is: 121.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.80 : 151.68 = 87.74 : x
  2. Step 2: Convert to fraction form
    109.80/151.68 = 87.74/x
  3. Step 3: Cross multiply
    109.80x = 151.68 × 87.74
  4. Step 4: Simplify right side
    109.80x = 13,308.40
  5. Step 5: Solve for x
    x = 13,308.40/109.80
  6. Step 6: Final answer
    x = 121.21

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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.