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Finding the Fourth Proportional to 665.79, 918.81 and 386.07

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Solution

The fourth proportional to 665.79, 918.81 and 386.07 is: 532.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.79 : 918.81 = 386.07 : x
  2. Step 2: Convert to fraction form
    665.79/918.81 = 386.07/x
  3. Step 3: Cross multiply
    665.79x = 918.81 × 386.07
  4. Step 4: Simplify right side
    665.79x = 354,724.98
  5. Step 5: Solve for x
    x = 354,724.98/665.79
  6. Step 6: Final answer
    x = 532.79

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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.