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Finding the Fourth Proportional to 101.21, 151.11 and 86.74

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Solution

The fourth proportional to 101.21, 151.11 and 86.74 is: 129.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.21 : 151.11 = 86.74 : x
  2. Step 2: Convert to fraction form
    101.21/151.11 = 86.74/x
  3. Step 3: Cross multiply
    101.21x = 151.11 × 86.74
  4. Step 4: Simplify right side
    101.21x = 13,106.90
  5. Step 5: Solve for x
    x = 13,106.90/101.21
  6. Step 6: Final answer
    x = 129.51

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.