Home / 1,280.34-1,766.79-720.90

Finding the Fourth Proportional to 1,280.34, 1,766.79 and 720.90

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Solution

The fourth proportional to 1,280.34, 1,766.79 and 720.90 is: 994.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.34 : 1,766.79 = 720.90 : x
  2. Step 2: Convert to fraction form
    1,280.34/1,766.79 = 720.90/x
  3. Step 3: Cross multiply
    1,280.34x = 1,766.79 × 720.90
  4. Step 4: Simplify right side
    1,280.34x = 1,273,678.91
  5. Step 5: Solve for x
    x = 1,273,678.91/1,280.34
  6. Step 6: Final answer
    x = 994.80

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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.