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Finding the Fourth Proportional to 1,078, 1,487.82 and 815.56

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Solution

The fourth proportional to 1,078, 1,487.82 and 815.56 is: 1,125.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,078 : 1,487.82 = 815.56 : x
  2. Step 2: Convert to fraction form
    1,078/1,487.82 = 815.56/x
  3. Step 3: Cross multiply
    1,078x = 1,487.82 × 815.56
  4. Step 4: Simplify right side
    1,078x = 1,213,406.48
  5. Step 5: Solve for x
    x = 1,213,406.48/1,078
  6. Step 6: Final answer
    x = 1,125.61

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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.