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Finding the Fourth Proportional to 485, 669.48 and 310.48

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Solution

The fourth proportional to 485, 669.48 and 310.48 is: 428.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    485 : 669.48 = 310.48 : x
  2. Step 2: Convert to fraction form
    485/669.48 = 310.48/x
  3. Step 3: Cross multiply
    485x = 669.48 × 310.48
  4. Step 4: Simplify right side
    485x = 207,860.15
  5. Step 5: Solve for x
    x = 207,860.15/485
  6. Step 6: Final answer
    x = 428.58

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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.