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Finding the Fourth Proportional to 611.82, 843.96 and 390.36

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Solution

The fourth proportional to 611.82, 843.96 and 390.36 is: 538.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.82 : 843.96 = 390.36 : x
  2. Step 2: Convert to fraction form
    611.82/843.96 = 390.36/x
  3. Step 3: Cross multiply
    611.82x = 843.96 × 390.36
  4. Step 4: Simplify right side
    611.82x = 329,448.23
  5. Step 5: Solve for x
    x = 329,448.23/611.82
  6. Step 6: Final answer
    x = 538.47

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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.