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Finding the Fourth Proportional to 642.82, 887.06 and 394.16

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Solution

The fourth proportional to 642.82, 887.06 and 394.16 is: 543.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.82 : 887.06 = 394.16 : x
  2. Step 2: Convert to fraction form
    642.82/887.06 = 394.16/x
  3. Step 3: Cross multiply
    642.82x = 887.06 × 394.16
  4. Step 4: Simplify right side
    642.82x = 349,643.57
  5. Step 5: Solve for x
    x = 349,643.57/642.82
  6. Step 6: Final answer
    x = 543.92

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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.