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Finding the Fourth Proportional to 1,230, 1,696.20 and 787.74

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Solution

The fourth proportional to 1,230, 1,696.20 and 787.74 is: 1,086.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,230 : 1,696.20 = 787.74 : x
  2. Step 2: Convert to fraction form
    1,230/1,696.20 = 787.74/x
  3. Step 3: Cross multiply
    1,230x = 1,696.20 × 787.74
  4. Step 4: Simplify right side
    1,230x = 1,336,164.59
  5. Step 5: Solve for x
    x = 1,336,164.59/1,230
  6. Step 6: Final answer
    x = 1,086.31

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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.