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Finding the Fourth Proportional to 665.61, 998.60 and 319.22

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Solution

The fourth proportional to 665.61, 998.60 and 319.22 is: 478.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.61 : 998.60 = 319.22 : x
  2. Step 2: Convert to fraction form
    665.61/998.60 = 319.22/x
  3. Step 3: Cross multiply
    665.61x = 998.60 × 319.22
  4. Step 4: Simplify right side
    665.61x = 318,766.50
  5. Step 5: Solve for x
    x = 318,766.50/665.61
  6. Step 6: Final answer
    x = 478.91

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.