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Finding the Fourth Proportional to 77.58, 114.90 and 76.78

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Solution

The fourth proportional to 77.58, 114.90 and 76.78 is: 113.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.58 : 114.90 = 76.78 : x
  2. Step 2: Convert to fraction form
    77.58/114.90 = 76.78/x
  3. Step 3: Cross multiply
    77.58x = 114.90 × 76.78
  4. Step 4: Simplify right side
    77.58x = 8,822.02
  5. Step 5: Solve for x
    x = 8,822.02/77.58
  6. Step 6: Final answer
    x = 113.72

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Why These Related Problems?

These problems maintain the same ratio (1.48) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.