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Finding the Fourth Proportional to 57.15, 78.71 and 54.45

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Solution

The fourth proportional to 57.15, 78.71 and 54.45 is: 74.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.15 : 78.71 = 54.45 : x
  2. Step 2: Convert to fraction form
    57.15/78.71 = 54.45/x
  3. Step 3: Cross multiply
    57.15x = 78.71 × 54.45
  4. Step 4: Simplify right side
    57.15x = 4,285.49
  5. Step 5: Solve for x
    x = 4,285.49/57.15
  6. Step 6: Final answer
    x = 74.99

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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.