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Finding the Fourth Proportional to 518.72, 778.15 and 258.86

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Solution

The fourth proportional to 518.72, 778.15 and 258.86 is: 388.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.72 : 778.15 = 258.86 : x
  2. Step 2: Convert to fraction form
    518.72/778.15 = 258.86/x
  3. Step 3: Cross multiply
    518.72x = 778.15 × 258.86
  4. Step 4: Simplify right side
    518.72x = 201,431.91
  5. Step 5: Solve for x
    x = 201,431.91/518.72
  6. Step 6: Final answer
    x = 388.32

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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.