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Finding the Fourth Proportional to 685.63, 1,028.35 and 338.98

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Solution

The fourth proportional to 685.63, 1,028.35 and 338.98 is: 508.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.63 : 1,028.35 = 338.98 : x
  2. Step 2: Convert to fraction form
    685.63/1,028.35 = 338.98/x
  3. Step 3: Cross multiply
    685.63x = 1,028.35 × 338.98
  4. Step 4: Simplify right side
    685.63x = 348,590.08
  5. Step 5: Solve for x
    x = 348,590.08/685.63
  6. Step 6: Final answer
    x = 508.42

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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.