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Finding the Fourth Proportional to 665.30, 917.97 and 399.66

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Solution

The fourth proportional to 665.30, 917.97 and 399.66 is: 551.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.30 : 917.97 = 399.66 : x
  2. Step 2: Convert to fraction form
    665.30/917.97 = 399.66/x
  3. Step 3: Cross multiply
    665.30x = 917.97 × 399.66
  4. Step 4: Simplify right side
    665.30x = 366,875.89
  5. Step 5: Solve for x
    x = 366,875.89/665.30
  6. Step 6: Final answer
    x = 551.44

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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.