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Finding the Fourth Proportional to 820.25, 1,131.77 and 488.80

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Solution

The fourth proportional to 820.25, 1,131.77 and 488.80 is: 674.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.25 : 1,131.77 = 488.80 : x
  2. Step 2: Convert to fraction form
    820.25/1,131.77 = 488.80/x
  3. Step 3: Cross multiply
    820.25x = 1,131.77 × 488.80
  4. Step 4: Simplify right side
    820.25x = 553,207.57
  5. Step 5: Solve for x
    x = 553,207.57/820.25
  6. Step 6: Final answer
    x = 674.44

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.