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Finding the Fourth Proportional to 860.68, 1,290.33 and 312.79

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Solution

The fourth proportional to 860.68, 1,290.33 and 312.79 is: 468.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.68 : 1,290.33 = 312.79 : x
  2. Step 2: Convert to fraction form
    860.68/1,290.33 = 312.79/x
  3. Step 3: Cross multiply
    860.68x = 1,290.33 × 312.79
  4. Step 4: Simplify right side
    860.68x = 403,597.89
  5. Step 5: Solve for x
    x = 403,597.89/860.68
  6. Step 6: Final answer
    x = 468.93

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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.