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Finding the Fourth Proportional to 620.40, 856.16 and 340.65

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Solution

The fourth proportional to 620.40, 856.16 and 340.65 is: 470.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.40 : 856.16 = 340.65 : x
  2. Step 2: Convert to fraction form
    620.40/856.16 = 340.65/x
  3. Step 3: Cross multiply
    620.40x = 856.16 × 340.65
  4. Step 4: Simplify right side
    620.40x = 291,645.99
  5. Step 5: Solve for x
    x = 291,645.99/620.40
  6. Step 6: Final answer
    x = 470.09

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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.