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Finding the Fourth Proportional to 100.08, 138.08 and 67.28

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Solution

The fourth proportional to 100.08, 138.08 and 67.28 is: 92.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.08 : 138.08 = 67.28 : x
  2. Step 2: Convert to fraction form
    100.08/138.08 = 67.28/x
  3. Step 3: Cross multiply
    100.08x = 138.08 × 67.28
  4. Step 4: Simplify right side
    100.08x = 9,290.02
  5. Step 5: Solve for x
    x = 9,290.02/100.08
  6. Step 6: Final answer
    x = 92.83

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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.