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Finding the Fourth Proportional to 661.80, 990.85 and 336.48

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Solution

The fourth proportional to 661.80, 990.85 and 336.48 is: 503.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.80 : 990.85 = 336.48 : x
  2. Step 2: Convert to fraction form
    661.80/990.85 = 336.48/x
  3. Step 3: Cross multiply
    661.80x = 990.85 × 336.48
  4. Step 4: Simplify right side
    661.80x = 333,401.21
  5. Step 5: Solve for x
    x = 333,401.21/661.80
  6. Step 6: Final answer
    x = 503.78

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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.