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Finding the Fourth Proportional to 390.12, 538.14 and 234.78

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Solution

The fourth proportional to 390.12, 538.14 and 234.78 is: 323.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.12 : 538.14 = 234.78 : x
  2. Step 2: Convert to fraction form
    390.12/538.14 = 234.78/x
  3. Step 3: Cross multiply
    390.12x = 538.14 × 234.78
  4. Step 4: Simplify right side
    390.12x = 126,344.51
  5. Step 5: Solve for x
    x = 126,344.51/390.12
  6. Step 6: Final answer
    x = 323.86

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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.