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Finding the Fourth Proportional to 612.90, 919.40 and 440.36

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Solution

The fourth proportional to 612.90, 919.40 and 440.36 is: 660.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.90 : 919.40 = 440.36 : x
  2. Step 2: Convert to fraction form
    612.90/919.40 = 440.36/x
  3. Step 3: Cross multiply
    612.90x = 919.40 × 440.36
  4. Step 4: Simplify right side
    612.90x = 404,860.19
  5. Step 5: Solve for x
    x = 404,860.19/612.90
  6. Step 6: Final answer
    x = 660.56

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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.