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Finding the Fourth Proportional to 100.94, 139.34 and 87.07

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Solution

The fourth proportional to 100.94, 139.34 and 87.07 is: 120.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.94 : 139.34 = 87.07 : x
  2. Step 2: Convert to fraction form
    100.94/139.34 = 87.07/x
  3. Step 3: Cross multiply
    100.94x = 139.34 × 87.07
  4. Step 4: Simplify right side
    100.94x = 12,132.33
  5. Step 5: Solve for x
    x = 12,132.33/100.94
  6. Step 6: Final answer
    x = 120.19

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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.