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Finding the Fourth Proportional to 665.85, 998.58 and 318.99

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Solution

The fourth proportional to 665.85, 998.58 and 318.99 is: 478.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.85 : 998.58 = 318.99 : x
  2. Step 2: Convert to fraction form
    665.85/998.58 = 318.99/x
  3. Step 3: Cross multiply
    665.85x = 998.58 × 318.99
  4. Step 4: Simplify right side
    665.85x = 318,537.03
  5. Step 5: Solve for x
    x = 318,537.03/665.85
  6. Step 6: Final answer
    x = 478.39

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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.