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Finding the Fourth Proportional to 765.06, 1,053.05 and 639.33

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Solution

The fourth proportional to 765.06, 1,053.05 and 639.33 is: 879.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.06 : 1,053.05 = 639.33 : x
  2. Step 2: Convert to fraction form
    765.06/1,053.05 = 639.33/x
  3. Step 3: Cross multiply
    765.06x = 1,053.05 × 639.33
  4. Step 4: Simplify right side
    765.06x = 673,243.26
  5. Step 5: Solve for x
    x = 673,243.26/765.06
  6. Step 6: Final answer
    x = 879.99

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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.