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Finding the Fourth Proportional to 145.78, 200.80 and 131.20

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Solution

The fourth proportional to 145.78, 200.80 and 131.20 is: 180.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.78 : 200.80 = 131.20 : x
  2. Step 2: Convert to fraction form
    145.78/200.80 = 131.20/x
  3. Step 3: Cross multiply
    145.78x = 200.80 × 131.20
  4. Step 4: Simplify right side
    145.78x = 26,344.96
  5. Step 5: Solve for x
    x = 26,344.96/145.78
  6. Step 6: Final answer
    x = 180.72

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.