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Finding the Fourth Proportional to 720.82, 1,081.38 and 287.96

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Solution

The fourth proportional to 720.82, 1,081.38 and 287.96 is: 432.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.82 : 1,081.38 = 287.96 : x
  2. Step 2: Convert to fraction form
    720.82/1,081.38 = 287.96/x
  3. Step 3: Cross multiply
    720.82x = 1,081.38 × 287.96
  4. Step 4: Simplify right side
    720.82x = 311,394.18
  5. Step 5: Solve for x
    x = 311,394.18/720.82
  6. Step 6: Final answer
    x = 432.00

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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.