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Finding the Fourth Proportional to 518.22, 715.47 and 321.78

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Solution

The fourth proportional to 518.22, 715.47 and 321.78 is: 444.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.22 : 715.47 = 321.78 : x
  2. Step 2: Convert to fraction form
    518.22/715.47 = 321.78/x
  3. Step 3: Cross multiply
    518.22x = 715.47 × 321.78
  4. Step 4: Simplify right side
    518.22x = 230,223.94
  5. Step 5: Solve for x
    x = 230,223.94/518.22
  6. Step 6: Final answer
    x = 444.26

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.