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Finding the Fourth Proportional to 620.79, 856.65 and 355.26

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Solution

The fourth proportional to 620.79, 856.65 and 355.26 is: 490.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.79 : 856.65 = 355.26 : x
  2. Step 2: Convert to fraction form
    620.79/856.65 = 355.26/x
  3. Step 3: Cross multiply
    620.79x = 856.65 × 355.26
  4. Step 4: Simplify right side
    620.79x = 304,333.48
  5. Step 5: Solve for x
    x = 304,333.48/620.79
  6. Step 6: Final answer
    x = 490.24

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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.