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Finding the Fourth Proportional to 666.51, 919.79 and 371.80

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Solution

The fourth proportional to 666.51, 919.79 and 371.80 is: 513.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.51 : 919.79 = 371.80 : x
  2. Step 2: Convert to fraction form
    666.51/919.79 = 371.80/x
  3. Step 3: Cross multiply
    666.51x = 919.79 × 371.80
  4. Step 4: Simplify right side
    666.51x = 341,977.92
  5. Step 5: Solve for x
    x = 341,977.92/666.51
  6. Step 6: Final answer
    x = 513.09

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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.