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Finding the Fourth Proportional to 859.28, 1,288.90 and 311.25

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Solution

The fourth proportional to 859.28, 1,288.90 and 311.25 is: 466.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.28 : 1,288.90 = 311.25 : x
  2. Step 2: Convert to fraction form
    859.28/1,288.90 = 311.25/x
  3. Step 3: Cross multiply
    859.28x = 1,288.90 × 311.25
  4. Step 4: Simplify right side
    859.28x = 401,170.13
  5. Step 5: Solve for x
    x = 401,170.13/859.28
  6. Step 6: Final answer
    x = 466.87

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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.