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Finding the Fourth Proportional to 665.89, 918.91 and 386.06

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Solution

The fourth proportional to 665.89, 918.91 and 386.06 is: 532.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.89 : 918.91 = 386.06 : x
  2. Step 2: Convert to fraction form
    665.89/918.91 = 386.06/x
  3. Step 3: Cross multiply
    665.89x = 918.91 × 386.06
  4. Step 4: Simplify right side
    665.89x = 354,750.28
  5. Step 5: Solve for x
    x = 354,750.28/665.89
  6. Step 6: Final answer
    x = 532.75

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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.