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Finding the Fourth Proportional to 860.12, 1,290.78 and 513.23

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Solution

The fourth proportional to 860.12, 1,290.78 and 513.23 is: 770.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.12 : 1,290.78 = 513.23 : x
  2. Step 2: Convert to fraction form
    860.12/1,290.78 = 513.23/x
  3. Step 3: Cross multiply
    860.12x = 1,290.78 × 513.23
  4. Step 4: Simplify right side
    860.12x = 662,464.45
  5. Step 5: Solve for x
    x = 662,464.45/860.12
  6. Step 6: Final answer
    x = 770.20

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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.