Home / 1,280.20-1,920.90-663.57

Finding the Fourth Proportional to 1,280.20, 1,920.90 and 663.57

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Solution

The fourth proportional to 1,280.20, 1,920.90 and 663.57 is: 995.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.20 : 1,920.90 = 663.57 : x
  2. Step 2: Convert to fraction form
    1,280.20/1,920.90 = 663.57/x
  3. Step 3: Cross multiply
    1,280.20x = 1,920.90 × 663.57
  4. Step 4: Simplify right side
    1,280.20x = 1,274,651.61
  5. Step 5: Solve for x
    x = 1,274,651.61/1,280.20
  6. Step 6: Final answer
    x = 995.67

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1.5x scale

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.