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Finding the Fourth Proportional to 858.63, 1,287.81 and 311.07

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Solution

The fourth proportional to 858.63, 1,287.81 and 311.07 is: 466.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.63 : 1,287.81 = 311.07 : x
  2. Step 2: Convert to fraction form
    858.63/1,287.81 = 311.07/x
  3. Step 3: Cross multiply
    858.63x = 1,287.81 × 311.07
  4. Step 4: Simplify right side
    858.63x = 400,599.06
  5. Step 5: Solve for x
    x = 400,599.06/858.63
  6. Step 6: Final answer
    x = 466.56

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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.