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Finding the Fourth Proportional to 858.99, 1,287.45 and 511.57

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Solution

The fourth proportional to 858.99, 1,287.45 and 511.57 is: 766.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.99 : 1,287.45 = 511.57 : x
  2. Step 2: Convert to fraction form
    858.99/1,287.45 = 511.57/x
  3. Step 3: Cross multiply
    858.99x = 1,287.45 × 511.57
  4. Step 4: Simplify right side
    858.99x = 658,620.80
  5. Step 5: Solve for x
    x = 658,620.80/858.99
  6. Step 6: Final answer
    x = 766.74

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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.