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Finding the Fourth Proportional to 57.00, 78.60 and 39.49

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Solution

The fourth proportional to 57.00, 78.60 and 39.49 is: 54.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.00 : 78.60 = 39.49 : x
  2. Step 2: Convert to fraction form
    57.00/78.60 = 39.49/x
  3. Step 3: Cross multiply
    57.00x = 78.60 × 39.49
  4. Step 4: Simplify right side
    57.00x = 3,103.87
  5. Step 5: Solve for x
    x = 3,103.87/57.00
  6. Step 6: Final answer
    x = 54.45

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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.