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Finding the Fourth Proportional to 612.20, 918.90 and 338.42

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Solution

The fourth proportional to 612.20, 918.90 and 338.42 is: 507.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.20 : 918.90 = 338.42 : x
  2. Step 2: Convert to fraction form
    612.20/918.90 = 338.42/x
  3. Step 3: Cross multiply
    612.20x = 918.90 × 338.42
  4. Step 4: Simplify right side
    612.20x = 310,976.44
  5. Step 5: Solve for x
    x = 310,976.44/612.20
  6. Step 6: Final answer
    x = 507.96

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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.