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Finding the Fourth Proportional to 1,680.79, 2,520.82 and 640.75

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Solution

The fourth proportional to 1,680.79, 2,520.82 and 640.75 is: 960.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,680.79 : 2,520.82 = 640.75 : x
  2. Step 2: Convert to fraction form
    1,680.79/2,520.82 = 640.75/x
  3. Step 3: Cross multiply
    1,680.79x = 2,520.82 × 640.75
  4. Step 4: Simplify right side
    1,680.79x = 1,615,215.42
  5. Step 5: Solve for x
    x = 1,615,215.42/1,680.79
  6. Step 6: Final answer
    x = 960.99

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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.