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Finding the Fourth Proportional to 642.24, 886.17 and 393.60

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Solution

The fourth proportional to 642.24, 886.17 and 393.60 is: 543.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.24 : 886.17 = 393.60 : x
  2. Step 2: Convert to fraction form
    642.24/886.17 = 393.60/x
  3. Step 3: Cross multiply
    642.24x = 886.17 × 393.60
  4. Step 4: Simplify right side
    642.24x = 348,796.51
  5. Step 5: Solve for x
    x = 348,796.51/642.24
  6. Step 6: Final answer
    x = 543.09

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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.