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Finding the Fourth Proportional to 100.70, 139.06 and 86.06

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Solution

The fourth proportional to 100.70, 139.06 and 86.06 is: 118.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.70 : 139.06 = 86.06 : x
  2. Step 2: Convert to fraction form
    100.70/139.06 = 86.06/x
  3. Step 3: Cross multiply
    100.70x = 139.06 × 86.06
  4. Step 4: Simplify right side
    100.70x = 11,966.59
  5. Step 5: Solve for x
    x = 11,966.59/100.70
  6. Step 6: Final answer
    x = 118.84

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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.