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Finding the Fourth Proportional to 779.96, 1,076.69 and 485.19

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Solution

The fourth proportional to 779.96, 1,076.69 and 485.19 is: 669.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    779.96 : 1,076.69 = 485.19 : x
  2. Step 2: Convert to fraction form
    779.96/1,076.69 = 485.19/x
  3. Step 3: Cross multiply
    779.96x = 1,076.69 × 485.19
  4. Step 4: Simplify right side
    779.96x = 522,400.43
  5. Step 5: Solve for x
    x = 522,400.43/779.96
  6. Step 6: Final answer
    x = 669.78

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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.