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Finding the Fourth Proportional to 259.75, 389.69 and 105.78

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Solution

The fourth proportional to 259.75, 389.69 and 105.78 is: 158.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    259.75 : 389.69 = 105.78 : x
  2. Step 2: Convert to fraction form
    259.75/389.69 = 105.78/x
  3. Step 3: Cross multiply
    259.75x = 389.69 × 105.78
  4. Step 4: Simplify right side
    259.75x = 41,220.88
  5. Step 5: Solve for x
    x = 41,220.88/259.75
  6. Step 6: Final answer
    x = 158.70

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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.