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Finding the Fourth Proportional to 661.66, 991.69 and 369.15

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Solution

The fourth proportional to 661.66, 991.69 and 369.15 is: 553.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.66 : 991.69 = 369.15 : x
  2. Step 2: Convert to fraction form
    661.66/991.69 = 369.15/x
  3. Step 3: Cross multiply
    661.66x = 991.69 × 369.15
  4. Step 4: Simplify right side
    661.66x = 366,082.36
  5. Step 5: Solve for x
    x = 366,082.36/661.66
  6. Step 6: Final answer
    x = 553.28

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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.