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Finding the Fourth Proportional to 611.54, 843.71 and 390.47

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Solution

The fourth proportional to 611.54, 843.71 and 390.47 is: 538.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.54 : 843.71 = 390.47 : x
  2. Step 2: Convert to fraction form
    611.54/843.71 = 390.47/x
  3. Step 3: Cross multiply
    611.54x = 843.71 × 390.47
  4. Step 4: Simplify right side
    611.54x = 329,437.27
  5. Step 5: Solve for x
    x = 329,437.27/611.54
  6. Step 6: Final answer
    x = 538.71

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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.