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Finding the Fourth Proportional to 871.39, 1,313.04 and 720.63

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Solution

The fourth proportional to 871.39, 1,313.04 and 720.63 is: 1,085.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.39 : 1,313.04 = 720.63 : x
  2. Step 2: Convert to fraction form
    871.39/1,313.04 = 720.63/x
  3. Step 3: Cross multiply
    871.39x = 1,313.04 × 720.63
  4. Step 4: Simplify right side
    871.39x = 946,218.72
  5. Step 5: Solve for x
    x = 946,218.72/871.39
  6. Step 6: Final answer
    x = 1,085.87

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.