Home / 1,420.15-2,128.20-986.80

Finding the Fourth Proportional to 1,420.15, 2,128.20 and 986.80

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Solution

The fourth proportional to 1,420.15, 2,128.20 and 986.80 is: 1,478.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,420.15 : 2,128.20 = 986.80 : x
  2. Step 2: Convert to fraction form
    1,420.15/2,128.20 = 986.80/x
  3. Step 3: Cross multiply
    1,420.15x = 2,128.20 × 986.80
  4. Step 4: Simplify right side
    1,420.15x = 2,100,107.76
  5. Step 5: Solve for x
    x = 2,100,107.76/1,420.15
  6. Step 6: Final answer
    x = 1,478.79

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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.