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Finding the Fourth Proportional to 685.19, 1,026.25 and 318.87

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Solution

The fourth proportional to 685.19, 1,026.25 and 318.87 is: 477.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.19 : 1,026.25 = 318.87 : x
  2. Step 2: Convert to fraction form
    685.19/1,026.25 = 318.87/x
  3. Step 3: Cross multiply
    685.19x = 1,026.25 × 318.87
  4. Step 4: Simplify right side
    685.19x = 327,239.54
  5. Step 5: Solve for x
    x = 327,239.54/685.19
  6. Step 6: Final answer
    x = 477.59

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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.