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Finding the Fourth Proportional to 100.07, 138.12 and 63.28

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Solution

The fourth proportional to 100.07, 138.12 and 63.28 is: 87.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.07 : 138.12 = 63.28 : x
  2. Step 2: Convert to fraction form
    100.07/138.12 = 63.28/x
  3. Step 3: Cross multiply
    100.07x = 138.12 × 63.28
  4. Step 4: Simplify right side
    100.07x = 8,739.54
  5. Step 5: Solve for x
    x = 8,739.54/100.07
  6. Step 6: Final answer
    x = 87.34

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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.