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Finding the Fourth Proportional to 389.90, 538.04 and 212.86

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Solution

The fourth proportional to 389.90, 538.04 and 212.86 is: 293.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.90 : 538.04 = 212.86 : x
  2. Step 2: Convert to fraction form
    389.90/538.04 = 212.86/x
  3. Step 3: Cross multiply
    389.90x = 538.04 × 212.86
  4. Step 4: Simplify right side
    389.90x = 114,525.37
  5. Step 5: Solve for x
    x = 114,525.37/389.90
  6. Step 6: Final answer
    x = 293.73

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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.