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Finding the Fourth Proportional to 518.58, 777.90 and 172.15

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Solution

The fourth proportional to 518.58, 777.90 and 172.15 is: 258.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.58 : 777.90 = 172.15 : x
  2. Step 2: Convert to fraction form
    518.58/777.90 = 172.15/x
  3. Step 3: Cross multiply
    518.58x = 777.90 × 172.15
  4. Step 4: Simplify right side
    518.58x = 133,915.56
  5. Step 5: Solve for x
    x = 133,915.56/518.58
  6. Step 6: Final answer
    x = 258.24

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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.