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Finding the Fourth Proportional to 100.90, 139.14 and 69.82

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Solution

The fourth proportional to 100.90, 139.14 and 69.82 is: 96.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.90 : 139.14 = 69.82 : x
  2. Step 2: Convert to fraction form
    100.90/139.14 = 69.82/x
  3. Step 3: Cross multiply
    100.90x = 139.14 × 69.82
  4. Step 4: Simplify right side
    100.90x = 9,714.75
  5. Step 5: Solve for x
    x = 9,714.75/100.90
  6. Step 6: Final answer
    x = 96.28

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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.