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Finding the Fourth Proportional to 641.40, 961.53 and 380.76

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Solution

The fourth proportional to 641.40, 961.53 and 380.76 is: 570.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.40 : 961.53 = 380.76 : x
  2. Step 2: Convert to fraction form
    641.40/961.53 = 380.76/x
  3. Step 3: Cross multiply
    641.40x = 961.53 × 380.76
  4. Step 4: Simplify right side
    641.40x = 366,112.16
  5. Step 5: Solve for x
    x = 366,112.16/641.40
  6. Step 6: Final answer
    x = 570.80

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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.