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Finding the Fourth Proportional to 642.72, 887.16 and 394.08

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Solution

The fourth proportional to 642.72, 887.16 and 394.08 is: 543.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.72 : 887.16 = 394.08 : x
  2. Step 2: Convert to fraction form
    642.72/887.16 = 394.08/x
  3. Step 3: Cross multiply
    642.72x = 887.16 × 394.08
  4. Step 4: Simplify right side
    642.72x = 349,612.01
  5. Step 5: Solve for x
    x = 349,612.01/642.72
  6. Step 6: Final answer
    x = 543.96

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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.