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Finding the Fourth Proportional to 865.07, 1,297.59 and 215.79

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Solution

The fourth proportional to 865.07, 1,297.59 and 215.79 is: 323.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.07 : 1,297.59 = 215.79 : x
  2. Step 2: Convert to fraction form
    865.07/1,297.59 = 215.79/x
  3. Step 3: Cross multiply
    865.07x = 1,297.59 × 215.79
  4. Step 4: Simplify right side
    865.07x = 280,006.95
  5. Step 5: Solve for x
    x = 280,006.95/865.07
  6. Step 6: Final answer
    x = 323.68

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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.