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Finding the Fourth Proportional to 57.08, 78.78 and 47.18

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Solution

The fourth proportional to 57.08, 78.78 and 47.18 is: 65.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.08 : 78.78 = 47.18 : x
  2. Step 2: Convert to fraction form
    57.08/78.78 = 47.18/x
  3. Step 3: Cross multiply
    57.08x = 78.78 × 47.18
  4. Step 4: Simplify right side
    57.08x = 3,716.84
  5. Step 5: Solve for x
    x = 3,716.84/57.08
  6. Step 6: Final answer
    x = 65.12

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.