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Finding the Fourth Proportional to 665.73, 918.90 and 386.15

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Solution

The fourth proportional to 665.73, 918.90 and 386.15 is: 532.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.73 : 918.90 = 386.15 : x
  2. Step 2: Convert to fraction form
    665.73/918.90 = 386.15/x
  3. Step 3: Cross multiply
    665.73x = 918.90 × 386.15
  4. Step 4: Simplify right side
    665.73x = 354,828.64
  5. Step 5: Solve for x
    x = 354,828.64/665.73
  6. Step 6: Final answer
    x = 532.99

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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.