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Finding the Fourth Proportional to 999.83, 1,379.07 and 917.21

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Solution

The fourth proportional to 999.83, 1,379.07 and 917.21 is: 1,265.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    999.83 : 1,379.07 = 917.21 : x
  2. Step 2: Convert to fraction form
    999.83/1,379.07 = 917.21/x
  3. Step 3: Cross multiply
    999.83x = 1,379.07 × 917.21
  4. Step 4: Simplify right side
    999.83x = 1,264,896.79
  5. Step 5: Solve for x
    x = 1,264,896.79/999.83
  6. Step 6: Final answer
    x = 1,265.11

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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.