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Finding the Fourth Proportional to 720.39, 1,080.75 and 207.39

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Solution

The fourth proportional to 720.39, 1,080.75 and 207.39 is: 311.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.39 : 1,080.75 = 207.39 : x
  2. Step 2: Convert to fraction form
    720.39/1,080.75 = 207.39/x
  3. Step 3: Cross multiply
    720.39x = 1,080.75 × 207.39
  4. Step 4: Simplify right side
    720.39x = 224,136.74
  5. Step 5: Solve for x
    x = 224,136.74/720.39
  6. Step 6: Final answer
    x = 311.13

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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.