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Finding the Fourth Proportional to 642.60, 889.38 and 626.40

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Solution

The fourth proportional to 642.60, 889.38 and 626.40 is: 866.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.60 : 889.38 = 626.40 : x
  2. Step 2: Convert to fraction form
    642.60/889.38 = 626.40/x
  3. Step 3: Cross multiply
    642.60x = 889.38 × 626.40
  4. Step 4: Simplify right side
    642.60x = 557,107.63
  5. Step 5: Solve for x
    x = 557,107.63/642.60
  6. Step 6: Final answer
    x = 866.96

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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.