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Finding the Fourth Proportional to 661.80, 991.26 and 553.26

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Solution

The fourth proportional to 661.80, 991.26 and 553.26 is: 828.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.80 : 991.26 = 553.26 : x
  2. Step 2: Convert to fraction form
    661.80/991.26 = 553.26/x
  3. Step 3: Cross multiply
    661.80x = 991.26 × 553.26
  4. Step 4: Simplify right side
    661.80x = 548,424.51
  5. Step 5: Solve for x
    x = 548,424.51/661.80
  6. Step 6: Final answer
    x = 828.69

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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.