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Finding the Fourth Proportional to 2,100.85, 3,151.95 and 640.15

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Solution

The fourth proportional to 2,100.85, 3,151.95 and 640.15 is: 960.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,100.85 : 3,151.95 = 640.15 : x
  2. Step 2: Convert to fraction form
    2,100.85/3,151.95 = 640.15/x
  3. Step 3: Cross multiply
    2,100.85x = 3,151.95 × 640.15
  4. Step 4: Simplify right side
    2,100.85x = 2,017,720.79
  5. Step 5: Solve for x
    x = 2,017,720.79/2,100.85
  6. Step 6: Final answer
    x = 960.43

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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.