Home / 1,319.20-1,983.60-1,290.40

Finding the Fourth Proportional to 1,319.20, 1,983.60 and 1,290.40

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Solution

The fourth proportional to 1,319.20, 1,983.60 and 1,290.40 is: 1,940.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,319.20 : 1,983.60 = 1,290.40 : x
  2. Step 2: Convert to fraction form
    1,319.20/1,983.60 = 1,290.40/x
  3. Step 3: Cross multiply
    1,319.20x = 1,983.60 × 1,290.40
  4. Step 4: Simplify right side
    1,319.20x = 2,559,637.44
  5. Step 5: Solve for x
    x = 2,559,637.44/1,319.20
  6. Step 6: Final answer
    x = 1,940.30

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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.