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Finding the Fourth Proportional to 143.50, 215.28 and 78.50

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Solution

The fourth proportional to 143.50, 215.28 and 78.50 is: 117.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.50 : 215.28 = 78.50 : x
  2. Step 2: Convert to fraction form
    143.50/215.28 = 78.50/x
  3. Step 3: Cross multiply
    143.50x = 215.28 × 78.50
  4. Step 4: Simplify right side
    143.50x = 16,899.48
  5. Step 5: Solve for x
    x = 16,899.48/143.50
  6. Step 6: Final answer
    x = 117.77

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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.