Home / 1,247.20-1,720.44-805.55

Finding the Fourth Proportional to 1,247.20, 1,720.44 and 805.55

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Solution

The fourth proportional to 1,247.20, 1,720.44 and 805.55 is: 1,111.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,247.20 : 1,720.44 = 805.55 : x
  2. Step 2: Convert to fraction form
    1,247.20/1,720.44 = 805.55/x
  3. Step 3: Cross multiply
    1,247.20x = 1,720.44 × 805.55
  4. Step 4: Simplify right side
    1,247.20x = 1,385,891.84
  5. Step 5: Solve for x
    x = 1,385,891.84/1,247.20
  6. Step 6: Final answer
    x = 1,111.20

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.