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Finding the Fourth Proportional to 489.75, 675.65 and 321.64

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Solution

The fourth proportional to 489.75, 675.65 and 321.64 is: 443.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.75 : 675.65 = 321.64 : x
  2. Step 2: Convert to fraction form
    489.75/675.65 = 321.64/x
  3. Step 3: Cross multiply
    489.75x = 675.65 × 321.64
  4. Step 4: Simplify right side
    489.75x = 217,316.07
  5. Step 5: Solve for x
    x = 217,316.07/489.75
  6. Step 6: Final answer
    x = 443.73

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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.