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Finding the Fourth Proportional to 853.68, 1,279.38 and 419.88

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Solution

The fourth proportional to 853.68, 1,279.38 and 419.88 is: 629.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.68 : 1,279.38 = 419.88 : x
  2. Step 2: Convert to fraction form
    853.68/1,279.38 = 419.88/x
  3. Step 3: Cross multiply
    853.68x = 1,279.38 × 419.88
  4. Step 4: Simplify right side
    853.68x = 537,186.07
  5. Step 5: Solve for x
    x = 537,186.07/853.68
  6. Step 6: Final answer
    x = 629.26

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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.