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Finding the Fourth Proportional to 860.56, 1,290.96 and 305.21

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Solution

The fourth proportional to 860.56, 1,290.96 and 305.21 is: 457.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.56 : 1,290.96 = 305.21 : x
  2. Step 2: Convert to fraction form
    860.56/1,290.96 = 305.21/x
  3. Step 3: Cross multiply
    860.56x = 1,290.96 × 305.21
  4. Step 4: Simplify right side
    860.56x = 394,017.13
  5. Step 5: Solve for x
    x = 394,017.13/860.56
  6. Step 6: Final answer
    x = 457.86

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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.