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Finding the Fourth Proportional to 865.11, 1,297.70 and 820.14

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Solution

The fourth proportional to 865.11, 1,297.70 and 820.14 is: 1,230.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.11 : 1,297.70 = 820.14 : x
  2. Step 2: Convert to fraction form
    865.11/1,297.70 = 820.14/x
  3. Step 3: Cross multiply
    865.11x = 1,297.70 × 820.14
  4. Step 4: Simplify right side
    865.11x = 1,064,289.79
  5. Step 5: Solve for x
    x = 1,064,289.79/865.11
  6. Step 6: Final answer
    x = 1,230.23

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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.