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Finding the Fourth Proportional to 820.47, 1,231.71 and 382.15

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Solution

The fourth proportional to 820.47, 1,231.71 and 382.15 is: 573.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.47 : 1,231.71 = 382.15 : x
  2. Step 2: Convert to fraction form
    820.47/1,231.71 = 382.15/x
  3. Step 3: Cross multiply
    820.47x = 1,231.71 × 382.15
  4. Step 4: Simplify right side
    820.47x = 470,697.98
  5. Step 5: Solve for x
    x = 470,697.98/820.47
  6. Step 6: Final answer
    x = 573.69

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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.