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Finding the Fourth Proportional to 678.56, 938.39 and 666.26

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Solution

The fourth proportional to 678.56, 938.39 and 666.26 is: 921.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.56 : 938.39 = 666.26 : x
  2. Step 2: Convert to fraction form
    678.56/938.39 = 666.26/x
  3. Step 3: Cross multiply
    678.56x = 938.39 × 666.26
  4. Step 4: Simplify right side
    678.56x = 625,203.70
  5. Step 5: Solve for x
    x = 625,203.70/678.56
  6. Step 6: Final answer
    x = 921.36

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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.