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Finding the Fourth Proportional to 665.80, 918.78 and 371.05

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Solution

The fourth proportional to 665.80, 918.78 and 371.05 is: 512.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.80 : 918.78 = 371.05 : x
  2. Step 2: Convert to fraction form
    665.80/918.78 = 371.05/x
  3. Step 3: Cross multiply
    665.80x = 918.78 × 371.05
  4. Step 4: Simplify right side
    665.80x = 340,913.32
  5. Step 5: Solve for x
    x = 340,913.32/665.80
  6. Step 6: Final answer
    x = 512.04

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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.