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Finding the Fourth Proportional to 809.71, 1,112 and 678.49

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Solution

The fourth proportional to 809.71, 1,112 and 678.49 is: 931.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.71 : 1,112 = 678.49 : x
  2. Step 2: Convert to fraction form
    809.71/1,112 = 678.49/x
  3. Step 3: Cross multiply
    809.71x = 1,112 × 678.49
  4. Step 4: Simplify right side
    809.71x = 754,480.88
  5. Step 5: Solve for x
    x = 754,480.88/809.71
  6. Step 6: Final answer
    x = 931.79

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.