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Finding the Fourth Proportional to 661.26, 991.64 and 198.95

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Solution

The fourth proportional to 661.26, 991.64 and 198.95 is: 298.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.26 : 991.64 = 198.95 : x
  2. Step 2: Convert to fraction form
    661.26/991.64 = 198.95/x
  3. Step 3: Cross multiply
    661.26x = 991.64 × 198.95
  4. Step 4: Simplify right side
    661.26x = 197,280.83
  5. Step 5: Solve for x
    x = 197,280.83/661.26
  6. Step 6: Final answer
    x = 298.34

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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.