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Finding the Fourth Proportional to 642.88, 965.88 and 411.84

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Solution

The fourth proportional to 642.88, 965.88 and 411.84 is: 618.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.88 : 965.88 = 411.84 : x
  2. Step 2: Convert to fraction form
    642.88/965.88 = 411.84/x
  3. Step 3: Cross multiply
    642.88x = 965.88 × 411.84
  4. Step 4: Simplify right side
    642.88x = 397,788.02
  5. Step 5: Solve for x
    x = 397,788.02/642.88
  6. Step 6: Final answer
    x = 618.76

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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.