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Finding the Fourth Proportional to 661.54, 990.33 and 400.75

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Solution

The fourth proportional to 661.54, 990.33 and 400.75 is: 599.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.54 : 990.33 = 400.75 : x
  2. Step 2: Convert to fraction form
    661.54/990.33 = 400.75/x
  3. Step 3: Cross multiply
    661.54x = 990.33 × 400.75
  4. Step 4: Simplify right side
    661.54x = 396,874.75
  5. Step 5: Solve for x
    x = 396,874.75/661.54
  6. Step 6: Final answer
    x = 599.93

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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.