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Finding the Fourth Proportional to 999.24, 1,379.08 and 720.40

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Solution

The fourth proportional to 999.24, 1,379.08 and 720.40 is: 994.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    999.24 : 1,379.08 = 720.40 : x
  2. Step 2: Convert to fraction form
    999.24/1,379.08 = 720.40/x
  3. Step 3: Cross multiply
    999.24x = 1,379.08 × 720.40
  4. Step 4: Simplify right side
    999.24x = 993,489.23
  5. Step 5: Solve for x
    x = 993,489.23/999.24
  6. Step 6: Final answer
    x = 994.24

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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.