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Finding the Fourth Proportional to 101.04, 139.21 and 87.40

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Solution

The fourth proportional to 101.04, 139.21 and 87.40 is: 120.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.04 : 139.21 = 87.40 : x
  2. Step 2: Convert to fraction form
    101.04/139.21 = 87.40/x
  3. Step 3: Cross multiply
    101.04x = 139.21 × 87.40
  4. Step 4: Simplify right side
    101.04x = 12,166.95
  5. Step 5: Solve for x
    x = 12,166.95/101.04
  6. Step 6: Final answer
    x = 120.42

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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.