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Finding the Fourth Proportional to 776.89, 1,072.09 and 422.80

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Solution

The fourth proportional to 776.89, 1,072.09 and 422.80 is: 583.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    776.89 : 1,072.09 = 422.80 : x
  2. Step 2: Convert to fraction form
    776.89/1,072.09 = 422.80/x
  3. Step 3: Cross multiply
    776.89x = 1,072.09 × 422.80
  4. Step 4: Simplify right side
    776.89x = 453,279.65
  5. Step 5: Solve for x
    x = 453,279.65/776.89
  6. Step 6: Final answer
    x = 583.45

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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.