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Finding the Fourth Proportional to 859.76, 1,289.08 and 513.15

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Solution

The fourth proportional to 859.76, 1,289.08 and 513.15 is: 769.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.76 : 1,289.08 = 513.15 : x
  2. Step 2: Convert to fraction form
    859.76/1,289.08 = 513.15/x
  3. Step 3: Cross multiply
    859.76x = 1,289.08 × 513.15
  4. Step 4: Simplify right side
    859.76x = 661,486.86
  5. Step 5: Solve for x
    x = 661,486.86/859.76
  6. Step 6: Final answer
    x = 769.38

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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.