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Finding the Fourth Proportional to 820.37, 1,130.09 and 778.68

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Solution

The fourth proportional to 820.37, 1,130.09 and 778.68 is: 1,072.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.37 : 1,130.09 = 778.68 : x
  2. Step 2: Convert to fraction form
    820.37/1,130.09 = 778.68/x
  3. Step 3: Cross multiply
    820.37x = 1,130.09 × 778.68
  4. Step 4: Simplify right side
    820.37x = 879,974.59
  5. Step 5: Solve for x
    x = 879,974.59/820.37
  6. Step 6: Final answer
    x = 1,072.65

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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.