Home / 1,413.78-2,120.40-439.80

Finding the Fourth Proportional to 1,413.78, 2,120.40 and 439.80

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Solution

The fourth proportional to 1,413.78, 2,120.40 and 439.80 is: 659.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,413.78 : 2,120.40 = 439.80 : x
  2. Step 2: Convert to fraction form
    1,413.78/2,120.40 = 439.80/x
  3. Step 3: Cross multiply
    1,413.78x = 2,120.40 × 439.80
  4. Step 4: Simplify right side
    1,413.78x = 932,551.92
  5. Step 5: Solve for x
    x = 932,551.92/1,413.78
  6. Step 6: Final answer
    x = 659.62

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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.