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Finding the Fourth Proportional to 821.38, 1,225.94 and 756.28

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Solution

The fourth proportional to 821.38, 1,225.94 and 756.28 is: 1,128.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.38 : 1,225.94 = 756.28 : x
  2. Step 2: Convert to fraction form
    821.38/1,225.94 = 756.28/x
  3. Step 3: Cross multiply
    821.38x = 1,225.94 × 756.28
  4. Step 4: Simplify right side
    821.38x = 927,153.90
  5. Step 5: Solve for x
    x = 927,153.90/821.38
  6. Step 6: Final answer
    x = 1,128.78

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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.