Home / 1,420.26-2,128.77-688.74

Finding the Fourth Proportional to 1,420.26, 2,128.77 and 688.74

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Solution

The fourth proportional to 1,420.26, 2,128.77 and 688.74 is: 1,032.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,420.26 : 2,128.77 = 688.74 : x
  2. Step 2: Convert to fraction form
    1,420.26/2,128.77 = 688.74/x
  3. Step 3: Cross multiply
    1,420.26x = 2,128.77 × 688.74
  4. Step 4: Simplify right side
    1,420.26x = 1,466,169.05
  5. Step 5: Solve for x
    x = 1,466,169.05/1,420.26
  6. Step 6: Final answer
    x = 1,032.32

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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.