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Finding the Fourth Proportional to 685.54, 1,028.19 and 338.76

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Solution

The fourth proportional to 685.54, 1,028.19 and 338.76 is: 508.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.54 : 1,028.19 = 338.76 : x
  2. Step 2: Convert to fraction form
    685.54/1,028.19 = 338.76/x
  3. Step 3: Cross multiply
    685.54x = 1,028.19 × 338.76
  4. Step 4: Simplify right side
    685.54x = 348,305.16
  5. Step 5: Solve for x
    x = 348,305.16/685.54
  6. Step 6: Final answer
    x = 508.08

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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.