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Finding the Fourth Proportional to 661.34, 984.20 and 641.90

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Solution

The fourth proportional to 661.34, 984.20 and 641.90 is: 955.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.34 : 984.20 = 641.90 : x
  2. Step 2: Convert to fraction form
    661.34/984.20 = 641.90/x
  3. Step 3: Cross multiply
    661.34x = 984.20 × 641.90
  4. Step 4: Simplify right side
    661.34x = 631,757.98
  5. Step 5: Solve for x
    x = 631,757.98/661.34
  6. Step 6: Final answer
    x = 955.27

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.