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Finding the Fourth Proportional to 145.23, 217.79 and 87.40

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Solution

The fourth proportional to 145.23, 217.79 and 87.40 is: 131.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.23 : 217.79 = 87.40 : x
  2. Step 2: Convert to fraction form
    145.23/217.79 = 87.40/x
  3. Step 3: Cross multiply
    145.23x = 217.79 × 87.40
  4. Step 4: Simplify right side
    145.23x = 19,033.78
  5. Step 5: Solve for x
    x = 19,033.78/145.23
  6. Step 6: Final answer
    x = 131.06

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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.