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Finding the Fourth Proportional to 820.09, 1,131.89 and 505.51

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Solution

The fourth proportional to 820.09, 1,131.89 and 505.51 is: 697.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.09 : 1,131.89 = 505.51 : x
  2. Step 2: Convert to fraction form
    820.09/1,131.89 = 505.51/x
  3. Step 3: Cross multiply
    820.09x = 1,131.89 × 505.51
  4. Step 4: Simplify right side
    820.09x = 572,181.71
  5. Step 5: Solve for x
    x = 572,181.71/820.09
  6. Step 6: Final answer
    x = 697.71

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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.