Home / 1,280.09-1,766.38-720.43

Finding the Fourth Proportional to 1,280.09, 1,766.38 and 720.43

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Solution

The fourth proportional to 1,280.09, 1,766.38 and 720.43 is: 994.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.09 : 1,766.38 = 720.43 : x
  2. Step 2: Convert to fraction form
    1,280.09/1,766.38 = 720.43/x
  3. Step 3: Cross multiply
    1,280.09x = 1,766.38 × 720.43
  4. Step 4: Simplify right side
    1,280.09x = 1,272,553.14
  5. Step 5: Solve for x
    x = 1,272,553.14/1,280.09
  6. Step 6: Final answer
    x = 994.11

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1.5x scale

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.