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Finding the Fourth Proportional to 677.80, 939.31 and 664.84

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Solution

The fourth proportional to 677.80, 939.31 and 664.84 is: 921.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    677.80 : 939.31 = 664.84 : x
  2. Step 2: Convert to fraction form
    677.80/939.31 = 664.84/x
  3. Step 3: Cross multiply
    677.80x = 939.31 × 664.84
  4. Step 4: Simplify right side
    677.80x = 624,490.86
  5. Step 5: Solve for x
    x = 624,490.86/677.80
  6. Step 6: Final answer
    x = 921.35

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.