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Finding the Fourth Proportional to 852.72, 1,279.35 and 390.70

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Solution

The fourth proportional to 852.72, 1,279.35 and 390.70 is: 586.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    852.72 : 1,279.35 = 390.70 : x
  2. Step 2: Convert to fraction form
    852.72/1,279.35 = 390.70/x
  3. Step 3: Cross multiply
    852.72x = 1,279.35 × 390.70
  4. Step 4: Simplify right side
    852.72x = 499,842.05
  5. Step 5: Solve for x
    x = 499,842.05/852.72
  6. Step 6: Final answer
    x = 586.17

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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.