Home / 2,121.90-2,928.20-1,190.40

Finding the Fourth Proportional to 2,121.90, 2,928.20 and 1,190.40

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Solution

The fourth proportional to 2,121.90, 2,928.20 and 1,190.40 is: 1,642.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,121.90 : 2,928.20 = 1,190.40 : x
  2. Step 2: Convert to fraction form
    2,121.90/2,928.20 = 1,190.40/x
  3. Step 3: Cross multiply
    2,121.90x = 2,928.20 × 1,190.40
  4. Step 4: Simplify right side
    2,121.90x = 3,485,729.28
  5. Step 5: Solve for x
    x = 3,485,729.28/2,121.90
  6. Step 6: Final answer
    x = 1,642.74

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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.