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Finding the Fourth Proportional to 665.88, 918.36 and 578.40

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Solution

The fourth proportional to 665.88, 918.36 and 578.40 is: 797.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.88 : 918.36 = 578.40 : x
  2. Step 2: Convert to fraction form
    665.88/918.36 = 578.40/x
  3. Step 3: Cross multiply
    665.88x = 918.36 × 578.40
  4. Step 4: Simplify right side
    665.88x = 531,179.42
  5. Step 5: Solve for x
    x = 531,179.42/665.88
  6. Step 6: Final answer
    x = 797.71

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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.