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Finding the Fourth Proportional to 287.50, 431.31 and 105.15

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Solution

The fourth proportional to 287.50, 431.31 and 105.15 is: 157.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.50 : 431.31 = 105.15 : x
  2. Step 2: Convert to fraction form
    287.50/431.31 = 105.15/x
  3. Step 3: Cross multiply
    287.50x = 431.31 × 105.15
  4. Step 4: Simplify right side
    287.50x = 45,352.25
  5. Step 5: Solve for x
    x = 45,352.25/287.50
  6. Step 6: Final answer
    x = 157.75

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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.