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Finding the Fourth Proportional to 779.69, 1,076.36 and 485.05

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Solution

The fourth proportional to 779.69, 1,076.36 and 485.05 is: 669.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    779.69 : 1,076.36 = 485.05 : x
  2. Step 2: Convert to fraction form
    779.69/1,076.36 = 485.05/x
  3. Step 3: Cross multiply
    779.69x = 1,076.36 × 485.05
  4. Step 4: Simplify right side
    779.69x = 522,083.30
  5. Step 5: Solve for x
    x = 522,083.30/779.69
  6. Step 6: Final answer
    x = 669.61

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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.