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Finding the Fourth Proportional to 100.20, 138.10 and 75.63

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Solution

The fourth proportional to 100.20, 138.10 and 75.63 is: 104.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.20 : 138.10 = 75.63 : x
  2. Step 2: Convert to fraction form
    100.20/138.10 = 75.63/x
  3. Step 3: Cross multiply
    100.20x = 138.10 × 75.63
  4. Step 4: Simplify right side
    100.20x = 10,444.50
  5. Step 5: Solve for x
    x = 10,444.50/100.20
  6. Step 6: Final answer
    x = 104.24

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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.