Home / 1,120.12-1,680.40-389.50

Finding the Fourth Proportional to 1,120.12, 1,680.40 and 389.50

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Solution

The fourth proportional to 1,120.12, 1,680.40 and 389.50 is: 584.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,120.12 : 1,680.40 = 389.50 : x
  2. Step 2: Convert to fraction form
    1,120.12/1,680.40 = 389.50/x
  3. Step 3: Cross multiply
    1,120.12x = 1,680.40 × 389.50
  4. Step 4: Simplify right side
    1,120.12x = 654,515.80
  5. Step 5: Solve for x
    x = 654,515.80/1,120.12
  6. Step 6: Final answer
    x = 584.33

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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.