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Finding the Fourth Proportional to 778.88, 1,072.48 and 685.16

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Solution

The fourth proportional to 778.88, 1,072.48 and 685.16 is: 943.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.88 : 1,072.48 = 685.16 : x
  2. Step 2: Convert to fraction form
    778.88/1,072.48 = 685.16/x
  3. Step 3: Cross multiply
    778.88x = 1,072.48 × 685.16
  4. Step 4: Simplify right side
    778.88x = 734,820.40
  5. Step 5: Solve for x
    x = 734,820.40/778.88
  6. Step 6: Final answer
    x = 943.43

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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.