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Finding the Fourth Proportional to 286.91, 430.38 and 81.50

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Solution

The fourth proportional to 286.91, 430.38 and 81.50 is: 122.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.91 : 430.38 = 81.50 : x
  2. Step 2: Convert to fraction form
    286.91/430.38 = 81.50/x
  3. Step 3: Cross multiply
    286.91x = 430.38 × 81.50
  4. Step 4: Simplify right side
    286.91x = 35,075.56
  5. Step 5: Solve for x
    x = 35,075.56/286.91
  6. Step 6: Final answer
    x = 122.25

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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.