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Finding the Fourth Proportional to 665.39, 918.34 and 385.64

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Solution

The fourth proportional to 665.39, 918.34 and 385.64 is: 532.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.39 : 918.34 = 385.64 : x
  2. Step 2: Convert to fraction form
    665.39/918.34 = 385.64/x
  3. Step 3: Cross multiply
    665.39x = 918.34 × 385.64
  4. Step 4: Simplify right side
    665.39x = 354,146.71
  5. Step 5: Solve for x
    x = 354,146.71/665.39
  6. Step 6: Final answer
    x = 532.24

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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.