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Finding the Fourth Proportional to 620.78, 930.56 and 311.70

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Solution

The fourth proportional to 620.78, 930.56 and 311.70 is: 467.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.78 : 930.56 = 311.70 : x
  2. Step 2: Convert to fraction form
    620.78/930.56 = 311.70/x
  3. Step 3: Cross multiply
    620.78x = 930.56 × 311.70
  4. Step 4: Simplify right side
    620.78x = 290,053.99
  5. Step 5: Solve for x
    x = 290,053.99/620.78
  6. Step 6: Final answer
    x = 467.24

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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.