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Finding the Fourth Proportional to 78.68, 118.20 and 55.92

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Solution

The fourth proportional to 78.68, 118.20 and 55.92 is: 84.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.68 : 118.20 = 55.92 : x
  2. Step 2: Convert to fraction form
    78.68/118.20 = 55.92/x
  3. Step 3: Cross multiply
    78.68x = 118.20 × 55.92
  4. Step 4: Simplify right side
    78.68x = 6,609.74
  5. Step 5: Solve for x
    x = 6,609.74/78.68
  6. Step 6: Final answer
    x = 84.01

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.