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Finding the Fourth Proportional to 657.90, 905.22 and 643.32

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Solution

The fourth proportional to 657.90, 905.22 and 643.32 is: 885.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.90 : 905.22 = 643.32 : x
  2. Step 2: Convert to fraction form
    657.90/905.22 = 643.32/x
  3. Step 3: Cross multiply
    657.90x = 905.22 × 643.32
  4. Step 4: Simplify right side
    657.90x = 582,346.13
  5. Step 5: Solve for x
    x = 582,346.13/657.90
  6. Step 6: Final answer
    x = 885.16

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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.