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Finding the Fourth Proportional to 518.46, 780.31 and 389.16

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Solution

The fourth proportional to 518.46, 780.31 and 389.16 is: 585.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.46 : 780.31 = 389.16 : x
  2. Step 2: Convert to fraction form
    518.46/780.31 = 389.16/x
  3. Step 3: Cross multiply
    518.46x = 780.31 × 389.16
  4. Step 4: Simplify right side
    518.46x = 303,665.44
  5. Step 5: Solve for x
    x = 303,665.44/518.46
  6. Step 6: Final answer
    x = 585.71

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.