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Finding the Fourth Proportional to 1,370.72, 2,057.30 and 640.70

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Solution

The fourth proportional to 1,370.72, 2,057.30 and 640.70 is: 961.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,370.72 : 2,057.30 = 640.70 : x
  2. Step 2: Convert to fraction form
    1,370.72/2,057.30 = 640.70/x
  3. Step 3: Cross multiply
    1,370.72x = 2,057.30 × 640.70
  4. Step 4: Simplify right side
    1,370.72x = 1,318,112.11
  5. Step 5: Solve for x
    x = 1,318,112.11/1,370.72
  6. Step 6: Final answer
    x = 961.62

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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.