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Finding the Fourth Proportional to 821.09, 1,235.96 and 756.69

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Solution

The fourth proportional to 821.09, 1,235.96 and 756.69 is: 1,139.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.09 : 1,235.96 = 756.69 : x
  2. Step 2: Convert to fraction form
    821.09/1,235.96 = 756.69/x
  3. Step 3: Cross multiply
    821.09x = 1,235.96 × 756.69
  4. Step 4: Simplify right side
    821.09x = 935,234.79
  5. Step 5: Solve for x
    x = 935,234.79/821.09
  6. Step 6: Final answer
    x = 1,139.02

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.