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Finding the Fourth Proportional to 641.40, 961.39 and 422.11

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Solution

The fourth proportional to 641.40, 961.39 and 422.11 is: 632.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.40 : 961.39 = 422.11 : x
  2. Step 2: Convert to fraction form
    641.40/961.39 = 422.11/x
  3. Step 3: Cross multiply
    641.40x = 961.39 × 422.11
  4. Step 4: Simplify right side
    641.40x = 405,812.33
  5. Step 5: Solve for x
    x = 405,812.33/641.40
  6. Step 6: Final answer
    x = 632.70

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1.5x scale

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.