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Finding the Fourth Proportional to 100.80, 139.09 and 59.35

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Solution

The fourth proportional to 100.80, 139.09 and 59.35 is: 81.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.80 : 139.09 = 59.35 : x
  2. Step 2: Convert to fraction form
    100.80/139.09 = 59.35/x
  3. Step 3: Cross multiply
    100.80x = 139.09 × 59.35
  4. Step 4: Simplify right side
    100.80x = 8,254.99
  5. Step 5: Solve for x
    x = 8,254.99/100.80
  6. Step 6: Final answer
    x = 81.90

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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.