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Finding the Fourth Proportional to 77.85, 107.34 and 53.31

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Solution

The fourth proportional to 77.85, 107.34 and 53.31 is: 73.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.85 : 107.34 = 53.31 : x
  2. Step 2: Convert to fraction form
    77.85/107.34 = 53.31/x
  3. Step 3: Cross multiply
    77.85x = 107.34 × 53.31
  4. Step 4: Simplify right side
    77.85x = 5,722.30
  5. Step 5: Solve for x
    x = 5,722.30/77.85
  6. Step 6: Final answer
    x = 73.50

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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.