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Finding the Fourth Proportional to 413.40, 620.18 and 139.48

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Solution

The fourth proportional to 413.40, 620.18 and 139.48 is: 209.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    413.40 : 620.18 = 139.48 : x
  2. Step 2: Convert to fraction form
    413.40/620.18 = 139.48/x
  3. Step 3: Cross multiply
    413.40x = 620.18 × 139.48
  4. Step 4: Simplify right side
    413.40x = 86,502.71
  5. Step 5: Solve for x
    x = 86,502.71/413.40
  6. Step 6: Final answer
    x = 209.25

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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.