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Finding the Fourth Proportional to 807.40, 1,209.52 and 721.60

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Solution

The fourth proportional to 807.40, 1,209.52 and 721.60 is: 1,080.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.40 : 1,209.52 = 721.60 : x
  2. Step 2: Convert to fraction form
    807.40/1,209.52 = 721.60/x
  3. Step 3: Cross multiply
    807.40x = 1,209.52 × 721.60
  4. Step 4: Simplify right side
    807.40x = 872,789.63
  5. Step 5: Solve for x
    x = 872,789.63/807.40
  6. Step 6: Final answer
    x = 1,080.99

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.