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Finding the Fourth Proportional to 1,339.80, 1,848.92 and 780.39

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Solution

The fourth proportional to 1,339.80, 1,848.92 and 780.39 is: 1,076.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,339.80 : 1,848.92 = 780.39 : x
  2. Step 2: Convert to fraction form
    1,339.80/1,848.92 = 780.39/x
  3. Step 3: Cross multiply
    1,339.80x = 1,848.92 × 780.39
  4. Step 4: Simplify right side
    1,339.80x = 1,442,874.78
  5. Step 5: Solve for x
    x = 1,442,874.78/1,339.80
  6. Step 6: Final answer
    x = 1,076.93

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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.