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Finding the Fourth Proportional to 665.72, 918.82 and 400.18

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Solution

The fourth proportional to 665.72, 918.82 and 400.18 is: 552.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.72 : 918.82 = 400.18 : x
  2. Step 2: Convert to fraction form
    665.72/918.82 = 400.18/x
  3. Step 3: Cross multiply
    665.72x = 918.82 × 400.18
  4. Step 4: Simplify right side
    665.72x = 367,693.39
  5. Step 5: Solve for x
    x = 367,693.39/665.72
  6. Step 6: Final answer
    x = 552.32

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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.