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Finding the Fourth Proportional to 271.20, 406.68 and 78.78

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Solution

The fourth proportional to 271.20, 406.68 and 78.78 is: 118.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    271.20 : 406.68 = 78.78 : x
  2. Step 2: Convert to fraction form
    271.20/406.68 = 78.78/x
  3. Step 3: Cross multiply
    271.20x = 406.68 × 78.78
  4. Step 4: Simplify right side
    271.20x = 32,038.25
  5. Step 5: Solve for x
    x = 32,038.25/271.20
  6. Step 6: Final answer
    x = 118.14

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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.