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Finding the Fourth Proportional to 665.58, 918.29 and 385.80

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Solution

The fourth proportional to 665.58, 918.29 and 385.80 is: 532.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.58 : 918.29 = 385.80 : x
  2. Step 2: Convert to fraction form
    665.58/918.29 = 385.80/x
  3. Step 3: Cross multiply
    665.58x = 918.29 × 385.80
  4. Step 4: Simplify right side
    665.58x = 354,274.35
  5. Step 5: Solve for x
    x = 354,274.35/665.58
  6. Step 6: Final answer
    x = 532.28

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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.