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Finding the Fourth Proportional to 145.88, 218.70 and 128.56

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Solution

The fourth proportional to 145.88, 218.70 and 128.56 is: 192.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.88 : 218.70 = 128.56 : x
  2. Step 2: Convert to fraction form
    145.88/218.70 = 128.56/x
  3. Step 3: Cross multiply
    145.88x = 218.70 × 128.56
  4. Step 4: Simplify right side
    145.88x = 28,116.55
  5. Step 5: Solve for x
    x = 28,116.55/145.88
  6. Step 6: Final answer
    x = 192.74

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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.