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Finding the Fourth Proportional to 720.67, 1,080.86 and 258.43

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Solution

The fourth proportional to 720.67, 1,080.86 and 258.43 is: 387.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.67 : 1,080.86 = 258.43 : x
  2. Step 2: Convert to fraction form
    720.67/1,080.86 = 258.43/x
  3. Step 3: Cross multiply
    720.67x = 1,080.86 × 258.43
  4. Step 4: Simplify right side
    720.67x = 279,324.59
  5. Step 5: Solve for x
    x = 279,324.59/720.67
  6. Step 6: Final answer
    x = 387.59

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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.