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Finding the Fourth Proportional to 642.35, 959.63 and 409.39

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Solution

The fourth proportional to 642.35, 959.63 and 409.39 is: 611.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.35 : 959.63 = 409.39 : x
  2. Step 2: Convert to fraction form
    642.35/959.63 = 409.39/x
  3. Step 3: Cross multiply
    642.35x = 959.63 × 409.39
  4. Step 4: Simplify right side
    642.35x = 392,858.48
  5. Step 5: Solve for x
    x = 392,858.48/642.35
  6. Step 6: Final answer
    x = 611.59

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.