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Finding the Fourth Proportional to 389.85, 538.00 and 215.19

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Solution

The fourth proportional to 389.85, 538.00 and 215.19 is: 296.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.85 : 538.00 = 215.19 : x
  2. Step 2: Convert to fraction form
    389.85/538.00 = 215.19/x
  3. Step 3: Cross multiply
    389.85x = 538.00 × 215.19
  4. Step 4: Simplify right side
    389.85x = 115,773.03
  5. Step 5: Solve for x
    x = 115,773.03/389.85
  6. Step 6: Final answer
    x = 296.97

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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.