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Finding the Fourth Proportional to 858.05, 1,287.25 and 280.88

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Solution

The fourth proportional to 858.05, 1,287.25 and 280.88 is: 421.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.05 : 1,287.25 = 280.88 : x
  2. Step 2: Convert to fraction form
    858.05/1,287.25 = 280.88/x
  3. Step 3: Cross multiply
    858.05x = 1,287.25 × 280.88
  4. Step 4: Simplify right side
    858.05x = 361,555.64
  5. Step 5: Solve for x
    x = 361,555.64/858.05
  6. Step 6: Final answer
    x = 421.37

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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.