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Finding the Fourth Proportional to 666.63, 919.89 and 620.19

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Solution

The fourth proportional to 666.63, 919.89 and 620.19 is: 855.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.63 : 919.89 = 620.19 : x
  2. Step 2: Convert to fraction form
    666.63/919.89 = 620.19/x
  3. Step 3: Cross multiply
    666.63x = 919.89 × 620.19
  4. Step 4: Simplify right side
    666.63x = 570,506.58
  5. Step 5: Solve for x
    x = 570,506.58/666.63
  6. Step 6: Final answer
    x = 855.81

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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.