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Finding the Fourth Proportional to 886.38, 1,328.70 and 399.78

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Solution

The fourth proportional to 886.38, 1,328.70 and 399.78 is: 599.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    886.38 : 1,328.70 = 399.78 : x
  2. Step 2: Convert to fraction form
    886.38/1,328.70 = 399.78/x
  3. Step 3: Cross multiply
    886.38x = 1,328.70 × 399.78
  4. Step 4: Simplify right side
    886.38x = 531,187.69
  5. Step 5: Solve for x
    x = 531,187.69/886.38
  6. Step 6: Final answer
    x = 599.28

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.