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Finding the Fourth Proportional to 391.05, 583.79 and 309.78

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Solution

The fourth proportional to 391.05, 583.79 and 309.78 is: 462.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.05 : 583.79 = 309.78 : x
  2. Step 2: Convert to fraction form
    391.05/583.79 = 309.78/x
  3. Step 3: Cross multiply
    391.05x = 583.79 × 309.78
  4. Step 4: Simplify right side
    391.05x = 180,844.92
  5. Step 5: Solve for x
    x = 180,844.92/391.05
  6. Step 6: Final answer
    x = 462.46

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.