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Finding the Fourth Proportional to 1,240.40, 1,711.74 and 680.85

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Solution

The fourth proportional to 1,240.40, 1,711.74 and 680.85 is: 939.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,240.40 : 1,711.74 = 680.85 : x
  2. Step 2: Convert to fraction form
    1,240.40/1,711.74 = 680.85/x
  3. Step 3: Cross multiply
    1,240.40x = 1,711.74 × 680.85
  4. Step 4: Simplify right side
    1,240.40x = 1,165,438.18
  5. Step 5: Solve for x
    x = 1,165,438.18/1,240.40
  6. Step 6: Final answer
    x = 939.57

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1.5x scale

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.