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Finding the Fourth Proportional to 678.81, 936.61 and 413.39

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Solution

The fourth proportional to 678.81, 936.61 and 413.39 is: 570.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.81 : 936.61 = 413.39 : x
  2. Step 2: Convert to fraction form
    678.81/936.61 = 413.39/x
  3. Step 3: Cross multiply
    678.81x = 936.61 × 413.39
  4. Step 4: Simplify right side
    678.81x = 387,184.17
  5. Step 5: Solve for x
    x = 387,184.17/678.81
  6. Step 6: Final answer
    x = 570.39

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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.