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Finding the Fourth Proportional to 852.86, 1,279.13 and 390.65

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Solution

The fourth proportional to 852.86, 1,279.13 and 390.65 is: 585.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    852.86 : 1,279.13 = 390.65 : x
  2. Step 2: Convert to fraction form
    852.86/1,279.13 = 390.65/x
  3. Step 3: Cross multiply
    852.86x = 1,279.13 × 390.65
  4. Step 4: Simplify right side
    852.86x = 499,696.31
  5. Step 5: Solve for x
    x = 499,696.31/852.86
  6. Step 6: Final answer
    x = 585.90

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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.