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Finding the Fourth Proportional to 853.79, 1,279.72 and 415.47

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Solution

The fourth proportional to 853.79, 1,279.72 and 415.47 is: 622.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.79 : 1,279.72 = 415.47 : x
  2. Step 2: Convert to fraction form
    853.79/1,279.72 = 415.47/x
  3. Step 3: Cross multiply
    853.79x = 1,279.72 × 415.47
  4. Step 4: Simplify right side
    853.79x = 531,685.27
  5. Step 5: Solve for x
    x = 531,685.27/853.79
  6. Step 6: Final answer
    x = 622.74

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.