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Finding the Fourth Proportional to 860.66, 1,290.58 and 312.69

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Solution

The fourth proportional to 860.66, 1,290.58 and 312.69 is: 468.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.66 : 1,290.58 = 312.69 : x
  2. Step 2: Convert to fraction form
    860.66/1,290.58 = 312.69/x
  3. Step 3: Cross multiply
    860.66x = 1,290.58 × 312.69
  4. Step 4: Simplify right side
    860.66x = 403,550.68
  5. Step 5: Solve for x
    x = 403,550.68/860.66
  6. Step 6: Final answer
    x = 468.89

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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.