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Finding the Fourth Proportional to 661.19, 991.41 and 417.20

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Solution

The fourth proportional to 661.19, 991.41 and 417.20 is: 625.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.19 : 991.41 = 417.20 : x
  2. Step 2: Convert to fraction form
    661.19/991.41 = 417.20/x
  3. Step 3: Cross multiply
    661.19x = 991.41 × 417.20
  4. Step 4: Simplify right side
    661.19x = 413,611.29
  5. Step 5: Solve for x
    x = 413,611.29/661.19
  6. Step 6: Final answer
    x = 625.56

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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.