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Finding the Fourth Proportional to 259.66, 389.47 and 86.32

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Solution

The fourth proportional to 259.66, 389.47 and 86.32 is: 129.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    259.66 : 389.47 = 86.32 : x
  2. Step 2: Convert to fraction form
    259.66/389.47 = 86.32/x
  3. Step 3: Cross multiply
    259.66x = 389.47 × 86.32
  4. Step 4: Simplify right side
    259.66x = 33,618.62
  5. Step 5: Solve for x
    x = 33,618.62/259.66
  6. Step 6: Final answer
    x = 129.47

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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.