Home / 1,120.13-1,680.95-389.70

Finding the Fourth Proportional to 1,120.13, 1,680.95 and 389.70

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Solution

The fourth proportional to 1,120.13, 1,680.95 and 389.70 is: 584.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,120.13 : 1,680.95 = 389.70 : x
  2. Step 2: Convert to fraction form
    1,120.13/1,680.95 = 389.70/x
  3. Step 3: Cross multiply
    1,120.13x = 1,680.95 × 389.70
  4. Step 4: Simplify right side
    1,120.13x = 655,066.22
  5. Step 5: Solve for x
    x = 655,066.22/1,120.13
  6. Step 6: Final answer
    x = 584.81

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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.