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Finding the Fourth Proportional to 680.88, 1,019.40 and 620.40

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Solution

The fourth proportional to 680.88, 1,019.40 and 620.40 is: 928.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.88 : 1,019.40 = 620.40 : x
  2. Step 2: Convert to fraction form
    680.88/1,019.40 = 620.40/x
  3. Step 3: Cross multiply
    680.88x = 1,019.40 × 620.40
  4. Step 4: Simplify right side
    680.88x = 632,435.76
  5. Step 5: Solve for x
    x = 632,435.76/680.88
  6. Step 6: Final answer
    x = 928.85

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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.