Home / 3,987.70-5,981.68-1,390.84

Finding the Fourth Proportional to 3,987.70, 5,981.68 and 1,390.84

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Solution

The fourth proportional to 3,987.70, 5,981.68 and 1,390.84 is: 2,086.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,987.70 : 5,981.68 = 1,390.84 : x
  2. Step 2: Convert to fraction form
    3,987.70/5,981.68 = 1,390.84/x
  3. Step 3: Cross multiply
    3,987.70x = 5,981.68 × 1,390.84
  4. Step 4: Simplify right side
    3,987.70x = 8,319,546.60
  5. Step 5: Solve for x
    x = 8,319,546.60/3,987.70
  6. Step 6: Final answer
    x = 2,086.30

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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.