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Finding the Fourth Proportional to 858.69, 1,284.85 and 512.21

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Solution

The fourth proportional to 858.69, 1,284.85 and 512.21 is: 766.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.69 : 1,284.85 = 512.21 : x
  2. Step 2: Convert to fraction form
    858.69/1,284.85 = 512.21/x
  3. Step 3: Cross multiply
    858.69x = 1,284.85 × 512.21
  4. Step 4: Simplify right side
    858.69x = 658,113.99
  5. Step 5: Solve for x
    x = 658,113.99/858.69
  6. Step 6: Final answer
    x = 766.42

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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.