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Finding the Fourth Proportional to 620.78, 856.70 and 372.05

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Solution

The fourth proportional to 620.78, 856.70 and 372.05 is: 513.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.78 : 856.70 = 372.05 : x
  2. Step 2: Convert to fraction form
    620.78/856.70 = 372.05/x
  3. Step 3: Cross multiply
    620.78x = 856.70 × 372.05
  4. Step 4: Simplify right side
    620.78x = 318,732.39
  5. Step 5: Solve for x
    x = 318,732.39/620.78
  6. Step 6: Final answer
    x = 513.44

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.