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Finding the Fourth Proportional to 661.12, 990.55 and 400.33

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Solution

The fourth proportional to 661.12, 990.55 and 400.33 is: 599.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.12 : 990.55 = 400.33 : x
  2. Step 2: Convert to fraction form
    661.12/990.55 = 400.33/x
  3. Step 3: Cross multiply
    661.12x = 990.55 × 400.33
  4. Step 4: Simplify right side
    661.12x = 396,544.67
  5. Step 5: Solve for x
    x = 396,544.67/661.12
  6. Step 6: Final answer
    x = 599.81

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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.