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Finding the Fourth Proportional to 485.25, 669.78 and 330

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Solution

The fourth proportional to 485.25, 669.78 and 330 is: 455.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.25 : 669.78 = 330 : x
  2. Step 2: Convert to fraction form
    485.25/669.78 = 330/x
  3. Step 3: Cross multiply
    485.25x = 669.78 × 330
  4. Step 4: Simplify right side
    485.25x = 221,027.40
  5. Step 5: Solve for x
    x = 221,027.40/485.25
  6. Step 6: Final answer
    x = 455.49

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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.