Home / 3,987.28-5,980.92-1,390.20

Finding the Fourth Proportional to 3,987.28, 5,980.92 and 1,390.20

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Solution

The fourth proportional to 3,987.28, 5,980.92 and 1,390.20 is: 2,085.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,987.28 : 5,980.92 = 1,390.20 : x
  2. Step 2: Convert to fraction form
    3,987.28/5,980.92 = 1,390.20/x
  3. Step 3: Cross multiply
    3,987.28x = 5,980.92 × 1,390.20
  4. Step 4: Simplify right side
    3,987.28x = 8,314,674.98
  5. Step 5: Solve for x
    x = 8,314,674.98/3,987.28
  6. Step 6: Final answer
    x = 2,085.30

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Similar ratio
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1.5x scale

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.