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Finding the Fourth Proportional to 513.90, 771.20 and 205.75

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Solution

The fourth proportional to 513.90, 771.20 and 205.75 is: 308.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    513.90 : 771.20 = 205.75 : x
  2. Step 2: Convert to fraction form
    513.90/771.20 = 205.75/x
  3. Step 3: Cross multiply
    513.90x = 771.20 × 205.75
  4. Step 4: Simplify right side
    513.90x = 158,674.40
  5. Step 5: Solve for x
    x = 158,674.40/513.90
  6. Step 6: Final answer
    x = 308.77

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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.