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Finding the Fourth Proportional to 685.88, 1,029.31 and 275.12

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Solution

The fourth proportional to 685.88, 1,029.31 and 275.12 is: 412.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.88 : 1,029.31 = 275.12 : x
  2. Step 2: Convert to fraction form
    685.88/1,029.31 = 275.12/x
  3. Step 3: Cross multiply
    685.88x = 1,029.31 × 275.12
  4. Step 4: Simplify right side
    685.88x = 283,185.65
  5. Step 5: Solve for x
    x = 283,185.65/685.88
  6. Step 6: Final answer
    x = 412.88

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.