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Finding the Fourth Proportional to 871.30, 1,306.86 and 859.12

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Solution

The fourth proportional to 871.30, 1,306.86 and 859.12 is: 1,288.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.30 : 1,306.86 = 859.12 : x
  2. Step 2: Convert to fraction form
    871.30/1,306.86 = 859.12/x
  3. Step 3: Cross multiply
    871.30x = 1,306.86 × 859.12
  4. Step 4: Simplify right side
    871.30x = 1,122,749.56
  5. Step 5: Solve for x
    x = 1,122,749.56/871.30
  6. Step 6: Final answer
    x = 1,288.59

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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.