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Finding the Fourth Proportional to 661.99, 992.85 and 388.21

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Solution

The fourth proportional to 661.99, 992.85 and 388.21 is: 582.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.99 : 992.85 = 388.21 : x
  2. Step 2: Convert to fraction form
    661.99/992.85 = 388.21/x
  3. Step 3: Cross multiply
    661.99x = 992.85 × 388.21
  4. Step 4: Simplify right side
    661.99x = 385,434.30
  5. Step 5: Solve for x
    x = 385,434.30/661.99
  6. Step 6: Final answer
    x = 582.24

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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.