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Finding the Fourth Proportional to 661.15, 991.90 and 544.21

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Solution

The fourth proportional to 661.15, 991.90 and 544.21 is: 816.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.15 : 991.90 = 544.21 : x
  2. Step 2: Convert to fraction form
    661.15/991.90 = 544.21/x
  3. Step 3: Cross multiply
    661.15x = 991.90 × 544.21
  4. Step 4: Simplify right side
    661.15x = 539,801.90
  5. Step 5: Solve for x
    x = 539,801.90/661.15
  6. Step 6: Final answer
    x = 816.46

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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.