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Finding the Fourth Proportional to 860.63, 1,290.42 and 312.62

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Solution

The fourth proportional to 860.63, 1,290.42 and 312.62 is: 468.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.63 : 1,290.42 = 312.62 : x
  2. Step 2: Convert to fraction form
    860.63/1,290.42 = 312.62/x
  3. Step 3: Cross multiply
    860.63x = 1,290.42 × 312.62
  4. Step 4: Simplify right side
    860.63x = 403,404.65
  5. Step 5: Solve for x
    x = 403,404.65/860.63
  6. Step 6: Final answer
    x = 468.73

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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.