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Finding the Fourth Proportional to 78.84, 118.12 and 66.68

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Solution

The fourth proportional to 78.84, 118.12 and 66.68 is: 99.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.84 : 118.12 = 66.68 : x
  2. Step 2: Convert to fraction form
    78.84/118.12 = 66.68/x
  3. Step 3: Cross multiply
    78.84x = 118.12 × 66.68
  4. Step 4: Simplify right side
    78.84x = 7,876.24
  5. Step 5: Solve for x
    x = 7,876.24/78.84
  6. Step 6: Final answer
    x = 99.90

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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.