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Finding the Fourth Proportional to 145.28, 216.74 and 142.40

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Solution

The fourth proportional to 145.28, 216.74 and 142.40 is: 212.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.28 : 216.74 = 142.40 : x
  2. Step 2: Convert to fraction form
    145.28/216.74 = 142.40/x
  3. Step 3: Cross multiply
    145.28x = 216.74 × 142.40
  4. Step 4: Simplify right side
    145.28x = 30,863.78
  5. Step 5: Solve for x
    x = 30,863.78/145.28
  6. Step 6: Final answer
    x = 212.44

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.