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Finding the Fourth Proportional to 851.19, 1,276.79 and 389.12

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Solution

The fourth proportional to 851.19, 1,276.79 and 389.12 is: 583.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    851.19 : 1,276.79 = 389.12 : x
  2. Step 2: Convert to fraction form
    851.19/1,276.79 = 389.12/x
  3. Step 3: Cross multiply
    851.19x = 1,276.79 × 389.12
  4. Step 4: Simplify right side
    851.19x = 496,824.52
  5. Step 5: Solve for x
    x = 496,824.52/851.19
  6. Step 6: Final answer
    x = 583.68

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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.