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Finding the Fourth Proportional to 665.05, 917.67 and 399.43

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Solution

The fourth proportional to 665.05, 917.67 and 399.43 is: 551.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.05 : 917.67 = 399.43 : x
  2. Step 2: Convert to fraction form
    665.05/917.67 = 399.43/x
  3. Step 3: Cross multiply
    665.05x = 917.67 × 399.43
  4. Step 4: Simplify right side
    665.05x = 366,544.93
  5. Step 5: Solve for x
    x = 366,544.93/665.05
  6. Step 6: Final answer
    x = 551.15

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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.