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Finding the Fourth Proportional to 78.81, 118.08 and 55.87

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Solution

The fourth proportional to 78.81, 118.08 and 55.87 is: 83.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.81 : 118.08 = 55.87 : x
  2. Step 2: Convert to fraction form
    78.81/118.08 = 55.87/x
  3. Step 3: Cross multiply
    78.81x = 118.08 × 55.87
  4. Step 4: Simplify right side
    78.81x = 6,597.20
  5. Step 5: Solve for x
    x = 6,597.20/78.81
  6. Step 6: Final answer
    x = 83.71

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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.