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Finding the Fourth Proportional to 665.87, 918.51 and 400.28

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Solution

The fourth proportional to 665.87, 918.51 and 400.28 is: 552.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.87 : 918.51 = 400.28 : x
  2. Step 2: Convert to fraction form
    665.87/918.51 = 400.28/x
  3. Step 3: Cross multiply
    665.87x = 918.51 × 400.28
  4. Step 4: Simplify right side
    665.87x = 367,661.18
  5. Step 5: Solve for x
    x = 367,661.18/665.87
  6. Step 6: Final answer
    x = 552.15

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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.