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Finding the Fourth Proportional to 485.05, 669.42 and 288.56

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Solution

The fourth proportional to 485.05, 669.42 and 288.56 is: 398.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.05 : 669.42 = 288.56 : x
  2. Step 2: Convert to fraction form
    485.05/669.42 = 288.56/x
  3. Step 3: Cross multiply
    485.05x = 669.42 × 288.56
  4. Step 4: Simplify right side
    485.05x = 193,167.84
  5. Step 5: Solve for x
    x = 193,167.84/485.05
  6. Step 6: Final answer
    x = 398.24

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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.