Home / 1,431.20-2,146.80-661.28

Finding the Fourth Proportional to 1,431.20, 2,146.80 and 661.28

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Solution

The fourth proportional to 1,431.20, 2,146.80 and 661.28 is: 991.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,431.20 : 2,146.80 = 661.28 : x
  2. Step 2: Convert to fraction form
    1,431.20/2,146.80 = 661.28/x
  3. Step 3: Cross multiply
    1,431.20x = 2,146.80 × 661.28
  4. Step 4: Simplify right side
    1,431.20x = 1,419,635.90
  5. Step 5: Solve for x
    x = 1,419,635.90/1,431.20
  6. Step 6: Final answer
    x = 991.92

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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.