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Finding the Fourth Proportional to 642.69, 961.53 and 489.06

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Solution

The fourth proportional to 642.69, 961.53 and 489.06 is: 731.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.69 : 961.53 = 489.06 : x
  2. Step 2: Convert to fraction form
    642.69/961.53 = 489.06/x
  3. Step 3: Cross multiply
    642.69x = 961.53 × 489.06
  4. Step 4: Simplify right side
    642.69x = 470,245.86
  5. Step 5: Solve for x
    x = 470,245.86/642.69
  6. Step 6: Final answer
    x = 731.68

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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.