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Finding the Fourth Proportional to 620.09, 855.14 and 420.95

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Solution

The fourth proportional to 620.09, 855.14 and 420.95 is: 580.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.09 : 855.14 = 420.95 : x
  2. Step 2: Convert to fraction form
    620.09/855.14 = 420.95/x
  3. Step 3: Cross multiply
    620.09x = 855.14 × 420.95
  4. Step 4: Simplify right side
    620.09x = 359,964.80
  5. Step 5: Solve for x
    x = 359,964.80/620.09
  6. Step 6: Final answer
    x = 580.51

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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.