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Finding the Fourth Proportional to 860.19, 1,287.09 and 513.72

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Solution

The fourth proportional to 860.19, 1,287.09 and 513.72 is: 768.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.19 : 1,287.09 = 513.72 : x
  2. Step 2: Convert to fraction form
    860.19/1,287.09 = 513.72/x
  3. Step 3: Cross multiply
    860.19x = 1,287.09 × 513.72
  4. Step 4: Simplify right side
    860.19x = 661,203.87
  5. Step 5: Solve for x
    x = 661,203.87/860.19
  6. Step 6: Final answer
    x = 768.67

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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.