Home / 1,280.50-1,920.80-403.60

Finding the Fourth Proportional to 1,280.50, 1,920.80 and 403.60

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Solution

The fourth proportional to 1,280.50, 1,920.80 and 403.60 is: 605.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.50 : 1,920.80 = 403.60 : x
  2. Step 2: Convert to fraction form
    1,280.50/1,920.80 = 403.60/x
  3. Step 3: Cross multiply
    1,280.50x = 1,920.80 × 403.60
  4. Step 4: Simplify right side
    1,280.50x = 775,234.88
  5. Step 5: Solve for x
    x = 775,234.88/1,280.50
  6. Step 6: Final answer
    x = 605.42

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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.