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Finding the Fourth Proportional to 1,286.28, 1,774.31 and 820.53

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Solution

The fourth proportional to 1,286.28, 1,774.31 and 820.53 is: 1,131.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,286.28 : 1,774.31 = 820.53 : x
  2. Step 2: Convert to fraction form
    1,286.28/1,774.31 = 820.53/x
  3. Step 3: Cross multiply
    1,286.28x = 1,774.31 × 820.53
  4. Step 4: Simplify right side
    1,286.28x = 1,455,870.48
  5. Step 5: Solve for x
    x = 1,455,870.48/1,286.28
  6. Step 6: Final answer
    x = 1,131.85

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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.