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Finding the Fourth Proportional to 620.75, 856.80 and 355.34

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Solution

The fourth proportional to 620.75, 856.80 and 355.34 is: 490.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.75 : 856.80 = 355.34 : x
  2. Step 2: Convert to fraction form
    620.75/856.80 = 355.34/x
  3. Step 3: Cross multiply
    620.75x = 856.80 × 355.34
  4. Step 4: Simplify right side
    620.75x = 304,453.63
  5. Step 5: Solve for x
    x = 304,453.63/620.75
  6. Step 6: Final answer
    x = 490.46

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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.