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Finding the Fourth Proportional to 999.60, 1,379.34 and 621.24

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Solution

The fourth proportional to 999.60, 1,379.34 and 621.24 is: 857.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    999.60 : 1,379.34 = 621.24 : x
  2. Step 2: Convert to fraction form
    999.60/1,379.34 = 621.24/x
  3. Step 3: Cross multiply
    999.60x = 1,379.34 × 621.24
  4. Step 4: Simplify right side
    999.60x = 856,901.18
  5. Step 5: Solve for x
    x = 856,901.18/999.60
  6. Step 6: Final answer
    x = 857.24

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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.