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Finding the Fourth Proportional to 772.56, 1,064.28 and 639.22

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Solution

The fourth proportional to 772.56, 1,064.28 and 639.22 is: 880.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    772.56 : 1,064.28 = 639.22 : x
  2. Step 2: Convert to fraction form
    772.56/1,064.28 = 639.22/x
  3. Step 3: Cross multiply
    772.56x = 1,064.28 × 639.22
  4. Step 4: Simplify right side
    772.56x = 680,309.06
  5. Step 5: Solve for x
    x = 680,309.06/772.56
  6. Step 6: Final answer
    x = 880.59

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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.