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Finding the Fourth Proportional to 820.65, 1,230.75 and 403.98

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Solution

The fourth proportional to 820.65, 1,230.75 and 403.98 is: 605.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.65 : 1,230.75 = 403.98 : x
  2. Step 2: Convert to fraction form
    820.65/1,230.75 = 403.98/x
  3. Step 3: Cross multiply
    820.65x = 1,230.75 × 403.98
  4. Step 4: Simplify right side
    820.65x = 497,198.39
  5. Step 5: Solve for x
    x = 497,198.39/820.65
  6. Step 6: Final answer
    x = 605.86

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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.