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Finding the Fourth Proportional to 389.89, 538.05 and 212.85

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Solution

The fourth proportional to 389.89, 538.05 and 212.85 is: 293.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.89 : 538.05 = 212.85 : x
  2. Step 2: Convert to fraction form
    389.89/538.05 = 212.85/x
  3. Step 3: Cross multiply
    389.89x = 538.05 × 212.85
  4. Step 4: Simplify right side
    389.89x = 114,525.35
  5. Step 5: Solve for x
    x = 114,525.35/389.89
  6. Step 6: Final answer
    x = 293.74

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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.