Home / 2,085.40-3,128.10-991.90

Finding the Fourth Proportional to 2,085.40, 3,128.10 and 991.90

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Solution

The fourth proportional to 2,085.40, 3,128.10 and 991.90 is: 1,487.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,085.40 : 3,128.10 = 991.90 : x
  2. Step 2: Convert to fraction form
    2,085.40/3,128.10 = 991.90/x
  3. Step 3: Cross multiply
    2,085.40x = 3,128.10 × 991.90
  4. Step 4: Simplify right side
    2,085.40x = 3,102,762.39
  5. Step 5: Solve for x
    x = 3,102,762.39/2,085.40
  6. Step 6: Final answer
    x = 1,487.85

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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.