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Finding the Fourth Proportional to 1,120.20, 1,679.84 and 427.12

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Solution

The fourth proportional to 1,120.20, 1,679.84 and 427.12 is: 640.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,120.20 : 1,679.84 = 427.12 : x
  2. Step 2: Convert to fraction form
    1,120.20/1,679.84 = 427.12/x
  3. Step 3: Cross multiply
    1,120.20x = 1,679.84 × 427.12
  4. Step 4: Simplify right side
    1,120.20x = 717,493.26
  5. Step 5: Solve for x
    x = 717,493.26/1,120.20
  6. Step 6: Final answer
    x = 640.50

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.