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Finding the Fourth Proportional to 808.57, 1,115.43 and 631.21

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Solution

The fourth proportional to 808.57, 1,115.43 and 631.21 is: 870.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.57 : 1,115.43 = 631.21 : x
  2. Step 2: Convert to fraction form
    808.57/1,115.43 = 631.21/x
  3. Step 3: Cross multiply
    808.57x = 1,115.43 × 631.21
  4. Step 4: Simplify right side
    808.57x = 704,070.57
  5. Step 5: Solve for x
    x = 704,070.57/808.57
  6. Step 6: Final answer
    x = 870.76

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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.