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Finding the Fourth Proportional to 390.57, 538.58 and 338.09

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Solution

The fourth proportional to 390.57, 538.58 and 338.09 is: 466.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.57 : 538.58 = 338.09 : x
  2. Step 2: Convert to fraction form
    390.57/538.58 = 338.09/x
  3. Step 3: Cross multiply
    390.57x = 538.58 × 338.09
  4. Step 4: Simplify right side
    390.57x = 182,086.66
  5. Step 5: Solve for x
    x = 182,086.66/390.57
  6. Step 6: Final answer
    x = 466.21

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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.