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Finding the Fourth Proportional to 389.77, 584.20 and 216.40

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Solution

The fourth proportional to 389.77, 584.20 and 216.40 is: 324.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.77 : 584.20 = 216.40 : x
  2. Step 2: Convert to fraction form
    389.77/584.20 = 216.40/x
  3. Step 3: Cross multiply
    389.77x = 584.20 × 216.40
  4. Step 4: Simplify right side
    389.77x = 126,419.69
  5. Step 5: Solve for x
    x = 126,419.69/389.77
  6. Step 6: Final answer
    x = 324.34

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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.