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Finding the Fourth Proportional to 642.78, 963.36 and 555.71

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Solution

The fourth proportional to 642.78, 963.36 and 555.71 is: 832.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.78 : 963.36 = 555.71 : x
  2. Step 2: Convert to fraction form
    642.78/963.36 = 555.71/x
  3. Step 3: Cross multiply
    642.78x = 963.36 × 555.71
  4. Step 4: Simplify right side
    642.78x = 535,343.97
  5. Step 5: Solve for x
    x = 535,343.97/642.78
  6. Step 6: Final answer
    x = 832.86

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.