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Finding the Fourth Proportional to 121.91, 183.58 and 87.91

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Solution

The fourth proportional to 121.91, 183.58 and 87.91 is: 132.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.91 : 183.58 = 87.91 : x
  2. Step 2: Convert to fraction form
    121.91/183.58 = 87.91/x
  3. Step 3: Cross multiply
    121.91x = 183.58 × 87.91
  4. Step 4: Simplify right side
    121.91x = 16,137.84
  5. Step 5: Solve for x
    x = 16,137.84/121.91
  6. Step 6: Final answer
    x = 132.37

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.