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Finding the Fourth Proportional to 853.07, 1,279.90 and 420.53

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Solution

The fourth proportional to 853.07, 1,279.90 and 420.53 is: 630.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.07 : 1,279.90 = 420.53 : x
  2. Step 2: Convert to fraction form
    853.07/1,279.90 = 420.53/x
  3. Step 3: Cross multiply
    853.07x = 1,279.90 × 420.53
  4. Step 4: Simplify right side
    853.07x = 538,227.84
  5. Step 5: Solve for x
    x = 538,227.84/853.07
  6. Step 6: Final answer
    x = 630.93

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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.