Home / 2,128.88-3,190.35-811.21

Finding the Fourth Proportional to 2,128.88, 3,190.35 and 811.21

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Solution

The fourth proportional to 2,128.88, 3,190.35 and 811.21 is: 1,215.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,128.88 : 3,190.35 = 811.21 : x
  2. Step 2: Convert to fraction form
    2,128.88/3,190.35 = 811.21/x
  3. Step 3: Cross multiply
    2,128.88x = 3,190.35 × 811.21
  4. Step 4: Simplify right side
    2,128.88x = 2,588,043.82
  5. Step 5: Solve for x
    x = 2,588,043.82/2,128.88
  6. Step 6: Final answer
    x = 1,215.68

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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.