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Finding the Fourth Proportional to 661.23, 989.35 and 411.11

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Solution

The fourth proportional to 661.23, 989.35 and 411.11 is: 615.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.23 : 989.35 = 411.11 : x
  2. Step 2: Convert to fraction form
    661.23/989.35 = 411.11/x
  3. Step 3: Cross multiply
    661.23x = 989.35 × 411.11
  4. Step 4: Simplify right side
    661.23x = 406,729.41
  5. Step 5: Solve for x
    x = 406,729.41/661.23
  6. Step 6: Final answer
    x = 615.11

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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.