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Finding the Fourth Proportional to 77.72, 107.21 and 53.12

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Solution

The fourth proportional to 77.72, 107.21 and 53.12 is: 73.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.72 : 107.21 = 53.12 : x
  2. Step 2: Convert to fraction form
    77.72/107.21 = 53.12/x
  3. Step 3: Cross multiply
    77.72x = 107.21 × 53.12
  4. Step 4: Simplify right side
    77.72x = 5,695.00
  5. Step 5: Solve for x
    x = 5,695.00/77.72
  6. Step 6: Final answer
    x = 73.27

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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.