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Finding the Fourth Proportional to 485.15, 726.43 and 387.19

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Solution

The fourth proportional to 485.15, 726.43 and 387.19 is: 579.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.15 : 726.43 = 387.19 : x
  2. Step 2: Convert to fraction form
    485.15/726.43 = 387.19/x
  3. Step 3: Cross multiply
    485.15x = 726.43 × 387.19
  4. Step 4: Simplify right side
    485.15x = 281,266.43
  5. Step 5: Solve for x
    x = 281,266.43/485.15
  6. Step 6: Final answer
    x = 579.75

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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.