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Finding the Fourth Proportional to 666.39, 919.42 and 427.20

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Solution

The fourth proportional to 666.39, 919.42 and 427.20 is: 589.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.39 : 919.42 = 427.20 : x
  2. Step 2: Convert to fraction form
    666.39/919.42 = 427.20/x
  3. Step 3: Cross multiply
    666.39x = 919.42 × 427.20
  4. Step 4: Simplify right side
    666.39x = 392,776.22
  5. Step 5: Solve for x
    x = 392,776.22/666.39
  6. Step 6: Final answer
    x = 589.41

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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.