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Finding the Fourth Proportional to 720.88, 1,081.40 and 310.05

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Solution

The fourth proportional to 720.88, 1,081.40 and 310.05 is: 465.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.88 : 1,081.40 = 310.05 : x
  2. Step 2: Convert to fraction form
    720.88/1,081.40 = 310.05/x
  3. Step 3: Cross multiply
    720.88x = 1,081.40 × 310.05
  4. Step 4: Simplify right side
    720.88x = 335,286.52
  5. Step 5: Solve for x
    x = 335,286.52/720.88
  6. Step 6: Final answer
    x = 465.11

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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.