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Finding the Fourth Proportional to 101.28, 151.21 and 86.84

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Solution

The fourth proportional to 101.28, 151.21 and 86.84 is: 129.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.28 : 151.21 = 86.84 : x
  2. Step 2: Convert to fraction form
    101.28/151.21 = 86.84/x
  3. Step 3: Cross multiply
    101.28x = 151.21 × 86.84
  4. Step 4: Simplify right side
    101.28x = 13,131.08
  5. Step 5: Solve for x
    x = 13,131.08/101.28
  6. Step 6: Final answer
    x = 129.65

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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.