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Finding the Fourth Proportional to 678.80, 936.57 and 399.01

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Solution

The fourth proportional to 678.80, 936.57 and 399.01 is: 550.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.80 : 936.57 = 399.01 : x
  2. Step 2: Convert to fraction form
    678.80/936.57 = 399.01/x
  3. Step 3: Cross multiply
    678.80x = 936.57 × 399.01
  4. Step 4: Simplify right side
    678.80x = 373,698.45
  5. Step 5: Solve for x
    x = 373,698.45/678.80
  6. Step 6: Final answer
    x = 550.53

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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.