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Finding the Fourth Proportional to 57.02, 78.77 and 55.31

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Solution

The fourth proportional to 57.02, 78.77 and 55.31 is: 76.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.02 : 78.77 = 55.31 : x
  2. Step 2: Convert to fraction form
    57.02/78.77 = 55.31/x
  3. Step 3: Cross multiply
    57.02x = 78.77 × 55.31
  4. Step 4: Simplify right side
    57.02x = 4,356.77
  5. Step 5: Solve for x
    x = 4,356.77/57.02
  6. Step 6: Final answer
    x = 76.41

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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.