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Finding the Fourth Proportional to 720.63, 1,080.81 and 287.73

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Solution

The fourth proportional to 720.63, 1,080.81 and 287.73 is: 431.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.63 : 1,080.81 = 287.73 : x
  2. Step 2: Convert to fraction form
    720.63/1,080.81 = 287.73/x
  3. Step 3: Cross multiply
    720.63x = 1,080.81 × 287.73
  4. Step 4: Simplify right side
    720.63x = 310,981.46
  5. Step 5: Solve for x
    x = 310,981.46/720.63
  6. Step 6: Final answer
    x = 431.54

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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.