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Finding the Fourth Proportional to 685.96, 1,028.48 and 320.56

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Solution

The fourth proportional to 685.96, 1,028.48 and 320.56 is: 480.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.96 : 1,028.48 = 320.56 : x
  2. Step 2: Convert to fraction form
    685.96/1,028.48 = 320.56/x
  3. Step 3: Cross multiply
    685.96x = 1,028.48 × 320.56
  4. Step 4: Simplify right side
    685.96x = 329,689.55
  5. Step 5: Solve for x
    x = 329,689.55/685.96
  6. Step 6: Final answer
    x = 480.63

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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.