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Finding the Fourth Proportional to 779.48, 1,076.24 and 485

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Solution

The fourth proportional to 779.48, 1,076.24 and 485 is: 669.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    779.48 : 1,076.24 = 485 : x
  2. Step 2: Convert to fraction form
    779.48/1,076.24 = 485/x
  3. Step 3: Cross multiply
    779.48x = 1,076.24 × 485
  4. Step 4: Simplify right side
    779.48x = 521,976.40
  5. Step 5: Solve for x
    x = 521,976.40/779.48
  6. Step 6: Final answer
    x = 669.65

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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.