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Finding the Fourth Proportional to 259.30, 388.91 and 85.96

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Solution

The fourth proportional to 259.30, 388.91 and 85.96 is: 128.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    259.30 : 388.91 = 85.96 : x
  2. Step 2: Convert to fraction form
    259.30/388.91 = 85.96/x
  3. Step 3: Cross multiply
    259.30x = 388.91 × 85.96
  4. Step 4: Simplify right side
    259.30x = 33,429.30
  5. Step 5: Solve for x
    x = 33,429.30/259.30
  6. Step 6: Final answer
    x = 128.92

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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.