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Finding the Fourth Proportional to 661.79, 913.22 and 399.75

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Solution

The fourth proportional to 661.79, 913.22 and 399.75 is: 551.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.79 : 913.22 = 399.75 : x
  2. Step 2: Convert to fraction form
    661.79/913.22 = 399.75/x
  3. Step 3: Cross multiply
    661.79x = 913.22 × 399.75
  4. Step 4: Simplify right side
    661.79x = 365,057.70
  5. Step 5: Solve for x
    x = 365,057.70/661.79
  6. Step 6: Final answer
    x = 551.63

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.