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Finding the Fourth Proportional to 1,679.54, 2,520.40 and 639.55

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Solution

The fourth proportional to 1,679.54, 2,520.40 and 639.55 is: 959.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,679.54 : 2,520.40 = 639.55 : x
  2. Step 2: Convert to fraction form
    1,679.54/2,520.40 = 639.55/x
  3. Step 3: Cross multiply
    1,679.54x = 2,520.40 × 639.55
  4. Step 4: Simplify right side
    1,679.54x = 1,611,910.39
  5. Step 5: Solve for x
    x = 1,611,910.39/1,679.54
  6. Step 6: Final answer
    x = 959.74

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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.