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Finding the Fourth Proportional to 77.02, 115.46 and 31.40

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Solution

The fourth proportional to 77.02, 115.46 and 31.40 is: 47.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.02 : 115.46 = 31.40 : x
  2. Step 2: Convert to fraction form
    77.02/115.46 = 31.40/x
  3. Step 3: Cross multiply
    77.02x = 115.46 × 31.40
  4. Step 4: Simplify right side
    77.02x = 3,625.44
  5. Step 5: Solve for x
    x = 3,625.44/77.02
  6. Step 6: Final answer
    x = 47.07

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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.