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Finding the Fourth Proportional to 687.09, 1,030.31 and 253.94

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Solution

The fourth proportional to 687.09, 1,030.31 and 253.94 is: 380.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.09 : 1,030.31 = 253.94 : x
  2. Step 2: Convert to fraction form
    687.09/1,030.31 = 253.94/x
  3. Step 3: Cross multiply
    687.09x = 1,030.31 × 253.94
  4. Step 4: Simplify right side
    687.09x = 261,634.98
  5. Step 5: Solve for x
    x = 261,634.98/687.09
  6. Step 6: Final answer
    x = 380.79

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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.