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Finding the Fourth Proportional to 611.67, 843.84 and 390.57

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Solution

The fourth proportional to 611.67, 843.84 and 390.57 is: 538.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.67 : 843.84 = 390.57 : x
  2. Step 2: Convert to fraction form
    611.67/843.84 = 390.57/x
  3. Step 3: Cross multiply
    611.67x = 843.84 × 390.57
  4. Step 4: Simplify right side
    611.67x = 329,578.59
  5. Step 5: Solve for x
    x = 329,578.59/611.67
  6. Step 6: Final answer
    x = 538.82

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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.