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Finding the Fourth Proportional to 858.23, 1,287.90 and 310.37

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Solution

The fourth proportional to 858.23, 1,287.90 and 310.37 is: 465.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.23 : 1,287.90 = 310.37 : x
  2. Step 2: Convert to fraction form
    858.23/1,287.90 = 310.37/x
  3. Step 3: Cross multiply
    858.23x = 1,287.90 × 310.37
  4. Step 4: Simplify right side
    858.23x = 399,719.08
  5. Step 5: Solve for x
    x = 399,719.08/858.23
  6. Step 6: Final answer
    x = 465.75

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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.