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Finding the Fourth Proportional to 853.30, 1,279.28 and 390.82

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Solution

The fourth proportional to 853.30, 1,279.28 and 390.82 is: 585.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.30 : 1,279.28 = 390.82 : x
  2. Step 2: Convert to fraction form
    853.30/1,279.28 = 390.82/x
  3. Step 3: Cross multiply
    853.30x = 1,279.28 × 390.82
  4. Step 4: Simplify right side
    853.30x = 499,968.21
  5. Step 5: Solve for x
    x = 499,968.21/853.30
  6. Step 6: Final answer
    x = 585.92

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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.