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Finding the Fourth Proportional to 259.41, 389.09 and 86.07

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Solution

The fourth proportional to 259.41, 389.09 and 86.07 is: 129.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    259.41 : 389.09 = 86.07 : x
  2. Step 2: Convert to fraction form
    259.41/389.09 = 86.07/x
  3. Step 3: Cross multiply
    259.41x = 389.09 × 86.07
  4. Step 4: Simplify right side
    259.41x = 33,488.98
  5. Step 5: Solve for x
    x = 33,488.98/259.41
  6. Step 6: Final answer
    x = 129.10

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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.