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Finding the Fourth Proportional to 1,680.60, 2,519.20 and 640.34

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Solution

The fourth proportional to 1,680.60, 2,519.20 and 640.34 is: 959.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,680.60 : 2,519.20 = 640.34 : x
  2. Step 2: Convert to fraction form
    1,680.60/2,519.20 = 640.34/x
  3. Step 3: Cross multiply
    1,680.60x = 2,519.20 × 640.34
  4. Step 4: Simplify right side
    1,680.60x = 1,613,144.53
  5. Step 5: Solve for x
    x = 1,613,144.53/1,680.60
  6. Step 6: Final answer
    x = 959.86

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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.