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Finding the Fourth Proportional to 858.11, 1,287.18 and 310.31

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Solution

The fourth proportional to 858.11, 1,287.18 and 310.31 is: 465.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.11 : 1,287.18 = 310.31 : x
  2. Step 2: Convert to fraction form
    858.11/1,287.18 = 310.31/x
  3. Step 3: Cross multiply
    858.11x = 1,287.18 × 310.31
  4. Step 4: Simplify right side
    858.11x = 399,424.83
  5. Step 5: Solve for x
    x = 399,424.83/858.11
  6. Step 6: Final answer
    x = 465.47

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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.