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Finding the Fourth Proportional to 1,380.57, 2,069.85 and 649.74

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Solution

The fourth proportional to 1,380.57, 2,069.85 and 649.74 is: 974.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,380.57 : 2,069.85 = 649.74 : x
  2. Step 2: Convert to fraction form
    1,380.57/2,069.85 = 649.74/x
  3. Step 3: Cross multiply
    1,380.57x = 2,069.85 × 649.74
  4. Step 4: Simplify right side
    1,380.57x = 1,344,864.34
  5. Step 5: Solve for x
    x = 1,344,864.34/1,380.57
  6. Step 6: Final answer
    x = 974.14

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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.