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Finding the Fourth Proportional to 78.11, 107.77 and 53.56

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Solution

The fourth proportional to 78.11, 107.77 and 53.56 is: 73.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.11 : 107.77 = 53.56 : x
  2. Step 2: Convert to fraction form
    78.11/107.77 = 53.56/x
  3. Step 3: Cross multiply
    78.11x = 107.77 × 53.56
  4. Step 4: Simplify right side
    78.11x = 5,772.03
  5. Step 5: Solve for x
    x = 5,772.03/78.11
  6. Step 6: Final answer
    x = 73.89

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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.