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Finding the Fourth Proportional to 999.90, 1,380.12 and 649.98

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Solution

The fourth proportional to 999.90, 1,380.12 and 649.98 is: 897.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    999.90 : 1,380.12 = 649.98 : x
  2. Step 2: Convert to fraction form
    999.90/1,380.12 = 649.98/x
  3. Step 3: Cross multiply
    999.90x = 1,380.12 × 649.98
  4. Step 4: Simplify right side
    999.90x = 897,050.40
  5. Step 5: Solve for x
    x = 897,050.40/999.90
  6. Step 6: Final answer
    x = 897.14

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.