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Finding the Fourth Proportional to 1,240.30, 1,711.62 and 680.79

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Solution

The fourth proportional to 1,240.30, 1,711.62 and 680.79 is: 939.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,240.30 : 1,711.62 = 680.79 : x
  2. Step 2: Convert to fraction form
    1,240.30/1,711.62 = 680.79/x
  3. Step 3: Cross multiply
    1,240.30x = 1,711.62 × 680.79
  4. Step 4: Simplify right side
    1,240.30x = 1,165,258.06
  5. Step 5: Solve for x
    x = 1,165,258.06/1,240.30
  6. Step 6: Final answer
    x = 939.50

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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.