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Finding the Fourth Proportional to 642.81, 963.45 and 369.21

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Solution

The fourth proportional to 642.81, 963.45 and 369.21 is: 553.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.81 : 963.45 = 369.21 : x
  2. Step 2: Convert to fraction form
    642.81/963.45 = 369.21/x
  3. Step 3: Cross multiply
    642.81x = 963.45 × 369.21
  4. Step 4: Simplify right side
    642.81x = 355,715.37
  5. Step 5: Solve for x
    x = 355,715.37/642.81
  6. Step 6: Final answer
    x = 553.38

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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.