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Finding the Fourth Proportional to 765.05, 1,147.29 and 399.80

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Solution

The fourth proportional to 765.05, 1,147.29 and 399.80 is: 599.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.05 : 1,147.29 = 399.80 : x
  2. Step 2: Convert to fraction form
    765.05/1,147.29 = 399.80/x
  3. Step 3: Cross multiply
    765.05x = 1,147.29 × 399.80
  4. Step 4: Simplify right side
    765.05x = 458,686.54
  5. Step 5: Solve for x
    x = 458,686.54/765.05
  6. Step 6: Final answer
    x = 599.55

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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.