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Finding the Fourth Proportional to 678.20, 936.37 and 439.38

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Solution

The fourth proportional to 678.20, 936.37 and 439.38 is: 606.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.20 : 936.37 = 439.38 : x
  2. Step 2: Convert to fraction form
    678.20/936.37 = 439.38/x
  3. Step 3: Cross multiply
    678.20x = 936.37 × 439.38
  4. Step 4: Simplify right side
    678.20x = 411,421.15
  5. Step 5: Solve for x
    x = 411,421.15/678.20
  6. Step 6: Final answer
    x = 606.63

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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.