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Finding the Fourth Proportional to 665.69, 998.63 and 319.20

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Solution

The fourth proportional to 665.69, 998.63 and 319.20 is: 478.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.69 : 998.63 = 319.20 : x
  2. Step 2: Convert to fraction form
    665.69/998.63 = 319.20/x
  3. Step 3: Cross multiply
    665.69x = 998.63 × 319.20
  4. Step 4: Simplify right side
    665.69x = 318,758.55
  5. Step 5: Solve for x
    x = 318,758.55/665.69
  6. Step 6: Final answer
    x = 478.84

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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.