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Finding the Fourth Proportional to 860.32, 1,290.38 and 312.46

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Solution

The fourth proportional to 860.32, 1,290.38 and 312.46 is: 468.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.32 : 1,290.38 = 312.46 : x
  2. Step 2: Convert to fraction form
    860.32/1,290.38 = 312.46/x
  3. Step 3: Cross multiply
    860.32x = 1,290.38 × 312.46
  4. Step 4: Simplify right side
    860.32x = 403,189.10
  5. Step 5: Solve for x
    x = 403,189.10/860.32
  6. Step 6: Final answer
    x = 468.65

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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.