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Finding the Fourth Proportional to 145.42, 217.90 and 80.36

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Solution

The fourth proportional to 145.42, 217.90 and 80.36 is: 120.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.42 : 217.90 = 80.36 : x
  2. Step 2: Convert to fraction form
    145.42/217.90 = 80.36/x
  3. Step 3: Cross multiply
    145.42x = 217.90 × 80.36
  4. Step 4: Simplify right side
    145.42x = 17,510.24
  5. Step 5: Solve for x
    x = 17,510.24/145.42
  6. Step 6: Final answer
    x = 120.42

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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.