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Finding the Fourth Proportional to 665.72, 918.78 and 456.11

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Solution

The fourth proportional to 665.72, 918.78 and 456.11 is: 629.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.72 : 918.78 = 456.11 : x
  2. Step 2: Convert to fraction form
    665.72/918.78 = 456.11/x
  3. Step 3: Cross multiply
    665.72x = 918.78 × 456.11
  4. Step 4: Simplify right side
    665.72x = 419,064.75
  5. Step 5: Solve for x
    x = 419,064.75/665.72
  6. Step 6: Final answer
    x = 629.49

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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.