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Finding the Fourth Proportional to 68.20, 93.84 and 66.40

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Solution

The fourth proportional to 68.20, 93.84 and 66.40 is: 91.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.20 : 93.84 = 66.40 : x
  2. Step 2: Convert to fraction form
    68.20/93.84 = 66.40/x
  3. Step 3: Cross multiply
    68.20x = 93.84 × 66.40
  4. Step 4: Simplify right side
    68.20x = 6,230.98
  5. Step 5: Solve for x
    x = 6,230.98/68.20
  6. Step 6: Final answer
    x = 91.36

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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.