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Finding the Fourth Proportional to 648.28, 889.49 and 642.16

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Solution

The fourth proportional to 648.28, 889.49 and 642.16 is: 881.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.28 : 889.49 = 642.16 : x
  2. Step 2: Convert to fraction form
    648.28/889.49 = 642.16/x
  3. Step 3: Cross multiply
    648.28x = 889.49 × 642.16
  4. Step 4: Simplify right side
    648.28x = 571,194.90
  5. Step 5: Solve for x
    x = 571,194.90/648.28
  6. Step 6: Final answer
    x = 881.09

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.