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Finding the Fourth Proportional to 485.23, 669.61 and 288.75

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Solution

The fourth proportional to 485.23, 669.61 and 288.75 is: 398.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.23 : 669.61 = 288.75 : x
  2. Step 2: Convert to fraction form
    485.23/669.61 = 288.75/x
  3. Step 3: Cross multiply
    485.23x = 669.61 × 288.75
  4. Step 4: Simplify right side
    485.23x = 193,349.89
  5. Step 5: Solve for x
    x = 193,349.89/485.23
  6. Step 6: Final answer
    x = 398.47

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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.