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Finding the Fourth Proportional to 666.91, 919.81 and 427.66

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Solution

The fourth proportional to 666.91, 919.81 and 427.66 is: 589.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.91 : 919.81 = 427.66 : x
  2. Step 2: Convert to fraction form
    666.91/919.81 = 427.66/x
  3. Step 3: Cross multiply
    666.91x = 919.81 × 427.66
  4. Step 4: Simplify right side
    666.91x = 393,365.41
  5. Step 5: Solve for x
    x = 393,365.41/666.91
  6. Step 6: Final answer
    x = 589.83

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1.5x scale

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.