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Finding the Fourth Proportional to 640, 882.79 and 378.10

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Solution

The fourth proportional to 640, 882.79 and 378.10 is: 521.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    640 : 882.79 = 378.10 : x
  2. Step 2: Convert to fraction form
    640/882.79 = 378.10/x
  3. Step 3: Cross multiply
    640x = 882.79 × 378.10
  4. Step 4: Simplify right side
    640x = 333,782.90
  5. Step 5: Solve for x
    x = 333,782.90/640
  6. Step 6: Final answer
    x = 521.54

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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.