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Finding the Fourth Proportional to 778.77, 1,073.80 and 638.44

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Solution

The fourth proportional to 778.77, 1,073.80 and 638.44 is: 880.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.77 : 1,073.80 = 638.44 : x
  2. Step 2: Convert to fraction form
    778.77/1,073.80 = 638.44/x
  3. Step 3: Cross multiply
    778.77x = 1,073.80 × 638.44
  4. Step 4: Simplify right side
    778.77x = 685,556.87
  5. Step 5: Solve for x
    x = 685,556.87/778.77
  6. Step 6: Final answer
    x = 880.31

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1.5x scale

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.