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Finding the Fourth Proportional to 78.61, 108.52 and 55.36

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Solution

The fourth proportional to 78.61, 108.52 and 55.36 is: 76.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.61 : 108.52 = 55.36 : x
  2. Step 2: Convert to fraction form
    78.61/108.52 = 55.36/x
  3. Step 3: Cross multiply
    78.61x = 108.52 × 55.36
  4. Step 4: Simplify right side
    78.61x = 6,007.39
  5. Step 5: Solve for x
    x = 6,007.39/78.61
  6. Step 6: Final answer
    x = 76.43

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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.