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Finding the Fourth Proportional to 720.38, 1,080.68 and 281.55

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Solution

The fourth proportional to 720.38, 1,080.68 and 281.55 is: 422.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.38 : 1,080.68 = 281.55 : x
  2. Step 2: Convert to fraction form
    720.38/1,080.68 = 281.55/x
  3. Step 3: Cross multiply
    720.38x = 1,080.68 × 281.55
  4. Step 4: Simplify right side
    720.38x = 304,268.10
  5. Step 5: Solve for x
    x = 304,268.10/720.38
  6. Step 6: Final answer
    x = 422.37

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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.