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Finding the Fourth Proportional to 86.83, 130.09 and 72.47

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Solution

The fourth proportional to 86.83, 130.09 and 72.47 is: 108.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.83 : 130.09 = 72.47 : x
  2. Step 2: Convert to fraction form
    86.83/130.09 = 72.47/x
  3. Step 3: Cross multiply
    86.83x = 130.09 × 72.47
  4. Step 4: Simplify right side
    86.83x = 9,427.62
  5. Step 5: Solve for x
    x = 9,427.62/86.83
  6. Step 6: Final answer
    x = 108.58

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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.