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Finding the Fourth Proportional to 121.35, 182.07 and 87.15

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Solution

The fourth proportional to 121.35, 182.07 and 87.15 is: 130.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.35 : 182.07 = 87.15 : x
  2. Step 2: Convert to fraction form
    121.35/182.07 = 87.15/x
  3. Step 3: Cross multiply
    121.35x = 182.07 × 87.15
  4. Step 4: Simplify right side
    121.35x = 15,867.40
  5. Step 5: Solve for x
    x = 15,867.40/121.35
  6. Step 6: Final answer
    x = 130.76

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.