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Finding the Fourth Proportional to 852.39, 1,278.19 and 390.06

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Solution

The fourth proportional to 852.39, 1,278.19 and 390.06 is: 584.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    852.39 : 1,278.19 = 390.06 : x
  2. Step 2: Convert to fraction form
    852.39/1,278.19 = 390.06/x
  3. Step 3: Cross multiply
    852.39x = 1,278.19 × 390.06
  4. Step 4: Simplify right side
    852.39x = 498,570.79
  5. Step 5: Solve for x
    x = 498,570.79/852.39
  6. Step 6: Final answer
    x = 584.91

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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.