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Finding the Fourth Proportional to 858.05, 1,288.80 and 512.06

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Solution

The fourth proportional to 858.05, 1,288.80 and 512.06 is: 769.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.05 : 1,288.80 = 512.06 : x
  2. Step 2: Convert to fraction form
    858.05/1,288.80 = 512.06/x
  3. Step 3: Cross multiply
    858.05x = 1,288.80 × 512.06
  4. Step 4: Simplify right side
    858.05x = 659,942.93
  5. Step 5: Solve for x
    x = 659,942.93/858.05
  6. Step 6: Final answer
    x = 769.12

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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.