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Finding the Fourth Proportional to 685.69, 1,028.43 and 338.93

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Solution

The fourth proportional to 685.69, 1,028.43 and 338.93 is: 508.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.69 : 1,028.43 = 338.93 : x
  2. Step 2: Convert to fraction form
    685.69/1,028.43 = 338.93/x
  3. Step 3: Cross multiply
    685.69x = 1,028.43 × 338.93
  4. Step 4: Simplify right side
    685.69x = 348,565.78
  5. Step 5: Solve for x
    x = 348,565.78/685.69
  6. Step 6: Final answer
    x = 508.34

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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.