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Finding the Fourth Proportional to 518.75, 778.25 and 172.20

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Solution

The fourth proportional to 518.75, 778.25 and 172.20 is: 258.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.75 : 778.25 = 172.20 : x
  2. Step 2: Convert to fraction form
    518.75/778.25 = 172.20/x
  3. Step 3: Cross multiply
    518.75x = 778.25 × 172.20
  4. Step 4: Simplify right side
    518.75x = 134,014.60
  5. Step 5: Solve for x
    x = 134,014.60/518.75
  6. Step 6: Final answer
    x = 258.34

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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.