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Finding the Fourth Proportional to 620.19, 855.51 and 395.72

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Solution

The fourth proportional to 620.19, 855.51 and 395.72 is: 545.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.19 : 855.51 = 395.72 : x
  2. Step 2: Convert to fraction form
    620.19/855.51 = 395.72/x
  3. Step 3: Cross multiply
    620.19x = 855.51 × 395.72
  4. Step 4: Simplify right side
    620.19x = 338,538.14
  5. Step 5: Solve for x
    x = 338,538.14/620.19
  6. Step 6: Final answer
    x = 545.86

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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.