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Finding the Fourth Proportional to 260.75, 391.12 and 78.14

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Solution

The fourth proportional to 260.75, 391.12 and 78.14 is: 117.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    260.75 : 391.12 = 78.14 : x
  2. Step 2: Convert to fraction form
    260.75/391.12 = 78.14/x
  3. Step 3: Cross multiply
    260.75x = 391.12 × 78.14
  4. Step 4: Simplify right side
    260.75x = 30,562.90
  5. Step 5: Solve for x
    x = 30,562.90/260.75
  6. Step 6: Final answer
    x = 117.21

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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.