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Finding the Fourth Proportional to 389.81, 537.97 and 215.21

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Solution

The fourth proportional to 389.81, 537.97 and 215.21 is: 297.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.81 : 537.97 = 215.21 : x
  2. Step 2: Convert to fraction form
    389.81/537.97 = 215.21/x
  3. Step 3: Cross multiply
    389.81x = 537.97 × 215.21
  4. Step 4: Simplify right side
    389.81x = 115,773.30
  5. Step 5: Solve for x
    x = 115,773.30/389.81
  6. Step 6: Final answer
    x = 297.00

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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.