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Finding the Fourth Proportional to 999.42, 1,379.21 and 579.86

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Solution

The fourth proportional to 999.42, 1,379.21 and 579.86 is: 800.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    999.42 : 1,379.21 = 579.86 : x
  2. Step 2: Convert to fraction form
    999.42/1,379.21 = 579.86/x
  3. Step 3: Cross multiply
    999.42x = 1,379.21 × 579.86
  4. Step 4: Simplify right side
    999.42x = 799,748.71
  5. Step 5: Solve for x
    x = 799,748.71/999.42
  6. Step 6: Final answer
    x = 800.21

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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.