Home / 2,129.85-2,939.25-1,290.70

Finding the Fourth Proportional to 2,129.85, 2,939.25 and 1,290.70

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Solution

The fourth proportional to 2,129.85, 2,939.25 and 1,290.70 is: 1,781.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,129.85 : 2,939.25 = 1,290.70 : x
  2. Step 2: Convert to fraction form
    2,129.85/2,939.25 = 1,290.70/x
  3. Step 3: Cross multiply
    2,129.85x = 2,939.25 × 1,290.70
  4. Step 4: Simplify right side
    2,129.85x = 3,793,689.98
  5. Step 5: Solve for x
    x = 3,793,689.98/2,129.85
  6. Step 6: Final answer
    x = 1,781.20

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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.