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Finding the Fourth Proportional to 259.49, 389.19 and 86.17

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Solution

The fourth proportional to 259.49, 389.19 and 86.17 is: 129.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    259.49 : 389.19 = 86.17 : x
  2. Step 2: Convert to fraction form
    259.49/389.19 = 86.17/x
  3. Step 3: Cross multiply
    259.49x = 389.19 × 86.17
  4. Step 4: Simplify right side
    259.49x = 33,536.50
  5. Step 5: Solve for x
    x = 33,536.50/259.49
  6. Step 6: Final answer
    x = 129.24

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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.