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Finding the Fourth Proportional to 865.69, 1,298.70 and 272.80

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Solution

The fourth proportional to 865.69, 1,298.70 and 272.80 is: 409.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.69 : 1,298.70 = 272.80 : x
  2. Step 2: Convert to fraction form
    865.69/1,298.70 = 272.80/x
  3. Step 3: Cross multiply
    865.69x = 1,298.70 × 272.80
  4. Step 4: Simplify right side
    865.69x = 354,286.98
  5. Step 5: Solve for x
    x = 354,286.98/865.69
  6. Step 6: Final answer
    x = 409.26

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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.