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Finding the Fourth Proportional to 145.62, 200.75 and 128.21

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Solution

The fourth proportional to 145.62, 200.75 and 128.21 is: 176.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.62 : 200.75 = 128.21 : x
  2. Step 2: Convert to fraction form
    145.62/200.75 = 128.21/x
  3. Step 3: Cross multiply
    145.62x = 200.75 × 128.21
  4. Step 4: Simplify right side
    145.62x = 25,736.51
  5. Step 5: Solve for x
    x = 25,736.51/145.62
  6. Step 6: Final answer
    x = 176.74

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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.