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Finding the Fourth Proportional to 67.80, 102.18 and 66.54

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Solution

The fourth proportional to 67.80, 102.18 and 66.54 is: 100.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    67.80 : 102.18 = 66.54 : x
  2. Step 2: Convert to fraction form
    67.80/102.18 = 66.54/x
  3. Step 3: Cross multiply
    67.80x = 102.18 × 66.54
  4. Step 4: Simplify right side
    67.80x = 6,799.06
  5. Step 5: Solve for x
    x = 6,799.06/67.80
  6. Step 6: Final answer
    x = 100.28

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.