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Finding the Fourth Proportional to 661.10, 990.38 and 371.66

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Solution

The fourth proportional to 661.10, 990.38 and 371.66 is: 556.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.10 : 990.38 = 371.66 : x
  2. Step 2: Convert to fraction form
    661.10/990.38 = 371.66/x
  3. Step 3: Cross multiply
    661.10x = 990.38 × 371.66
  4. Step 4: Simplify right side
    661.10x = 368,084.63
  5. Step 5: Solve for x
    x = 368,084.63/661.10
  6. Step 6: Final answer
    x = 556.78

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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.