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Finding the Fourth Proportional to 780.35, 1,078.88 and 745.92

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Solution

The fourth proportional to 780.35, 1,078.88 and 745.92 is: 1,031.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.35 : 1,078.88 = 745.92 : x
  2. Step 2: Convert to fraction form
    780.35/1,078.88 = 745.92/x
  3. Step 3: Cross multiply
    780.35x = 1,078.88 × 745.92
  4. Step 4: Simplify right side
    780.35x = 804,754.44
  5. Step 5: Solve for x
    x = 804,754.44/780.35
  6. Step 6: Final answer
    x = 1,031.28

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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.