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Finding the Fourth Proportional to 386.20, 578.61 and 203.72

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Solution

The fourth proportional to 386.20, 578.61 and 203.72 is: 305.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.20 : 578.61 = 203.72 : x
  2. Step 2: Convert to fraction form
    386.20/578.61 = 203.72/x
  3. Step 3: Cross multiply
    386.20x = 578.61 × 203.72
  4. Step 4: Simplify right side
    386.20x = 117,871.54
  5. Step 5: Solve for x
    x = 117,871.54/386.20
  6. Step 6: Final answer
    x = 305.21

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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.