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Finding the Fourth Proportional to 100.89, 139.31 and 65.95

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Solution

The fourth proportional to 100.89, 139.31 and 65.95 is: 91.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.89 : 139.31 = 65.95 : x
  2. Step 2: Convert to fraction form
    100.89/139.31 = 65.95/x
  3. Step 3: Cross multiply
    100.89x = 139.31 × 65.95
  4. Step 4: Simplify right side
    100.89x = 9,187.49
  5. Step 5: Solve for x
    x = 9,187.49/100.89
  6. Step 6: Final answer
    x = 91.06

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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.