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Finding the Fourth Proportional to 999.45, 1,379.16 and 579.78

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Solution

The fourth proportional to 999.45, 1,379.16 and 579.78 is: 800.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    999.45 : 1,379.16 = 579.78 : x
  2. Step 2: Convert to fraction form
    999.45/1,379.16 = 579.78/x
  3. Step 3: Cross multiply
    999.45x = 1,379.16 × 579.78
  4. Step 4: Simplify right side
    999.45x = 799,609.38
  5. Step 5: Solve for x
    x = 799,609.38/999.45
  6. Step 6: Final answer
    x = 800.05

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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.