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Finding the Fourth Proportional to 862.49, 1,285.16 and 820.65

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Solution

The fourth proportional to 862.49, 1,285.16 and 820.65 is: 1,222.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    862.49 : 1,285.16 = 820.65 : x
  2. Step 2: Convert to fraction form
    862.49/1,285.16 = 820.65/x
  3. Step 3: Cross multiply
    862.49x = 1,285.16 × 820.65
  4. Step 4: Simplify right side
    862.49x = 1,054,660.13
  5. Step 5: Solve for x
    x = 1,054,660.13/862.49
  6. Step 6: Final answer
    x = 1,222.82

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.