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Finding the Fourth Proportional to 413.51, 620.31 and 139.67

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Solution

The fourth proportional to 413.51, 620.31 and 139.67 is: 209.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    413.51 : 620.31 = 139.67 : x
  2. Step 2: Convert to fraction form
    413.51/620.31 = 139.67/x
  3. Step 3: Cross multiply
    413.51x = 620.31 × 139.67
  4. Step 4: Simplify right side
    413.51x = 86,635.60
  5. Step 5: Solve for x
    x = 86,635.60/413.51
  6. Step 6: Final answer
    x = 209.52

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.