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Finding the Fourth Proportional to 1,000.80, 1,380.24 and 720.90

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Solution

The fourth proportional to 1,000.80, 1,380.24 and 720.90 is: 994.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,000.80 : 1,380.24 = 720.90 : x
  2. Step 2: Convert to fraction form
    1,000.80/1,380.24 = 720.90/x
  3. Step 3: Cross multiply
    1,000.80x = 1,380.24 × 720.90
  4. Step 4: Simplify right side
    1,000.80x = 995,015.02
  5. Step 5: Solve for x
    x = 995,015.02/1,000.80
  6. Step 6: Final answer
    x = 994.22

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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.