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Finding the Fourth Proportional to 642.39, 886.32 and 409.56

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Solution

The fourth proportional to 642.39, 886.32 and 409.56 is: 565.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.39 : 886.32 = 409.56 : x
  2. Step 2: Convert to fraction form
    642.39/886.32 = 409.56/x
  3. Step 3: Cross multiply
    642.39x = 886.32 × 409.56
  4. Step 4: Simplify right side
    642.39x = 363,001.22
  5. Step 5: Solve for x
    x = 363,001.22/642.39
  6. Step 6: Final answer
    x = 565.08

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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.