Home / 1,405.12-2,109.30-860.80

Finding the Fourth Proportional to 1,405.12, 2,109.30 and 860.80

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Solution

The fourth proportional to 1,405.12, 2,109.30 and 860.80 is: 1,292.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,405.12 : 2,109.30 = 860.80 : x
  2. Step 2: Convert to fraction form
    1,405.12/2,109.30 = 860.80/x
  3. Step 3: Cross multiply
    1,405.12x = 2,109.30 × 860.80
  4. Step 4: Simplify right side
    1,405.12x = 1,815,685.44
  5. Step 5: Solve for x
    x = 1,815,685.44/1,405.12
  6. Step 6: Final answer
    x = 1,292.19

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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.