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Finding the Fourth Proportional to 640, 883.20 and 378.18

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Solution

The fourth proportional to 640, 883.20 and 378.18 is: 521.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    640 : 883.20 = 378.18 : x
  2. Step 2: Convert to fraction form
    640/883.20 = 378.18/x
  3. Step 3: Cross multiply
    640x = 883.20 × 378.18
  4. Step 4: Simplify right side
    640x = 334,008.58
  5. Step 5: Solve for x
    x = 334,008.58/640
  6. Step 6: Final answer
    x = 521.89

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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.