Home / 1,120.20-1,680.29-686.45

Finding the Fourth Proportional to 1,120.20, 1,680.29 and 686.45

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Solution

The fourth proportional to 1,120.20, 1,680.29 and 686.45 is: 1,029.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,120.20 : 1,680.29 = 686.45 : x
  2. Step 2: Convert to fraction form
    1,120.20/1,680.29 = 686.45/x
  3. Step 3: Cross multiply
    1,120.20x = 1,680.29 × 686.45
  4. Step 4: Simplify right side
    1,120.20x = 1,153,423.24
  5. Step 5: Solve for x
    x = 1,153,423.24/1,120.20
  6. Step 6: Final answer
    x = 1,029.66

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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.