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Finding the Fourth Proportional to 145.90, 201.81 and 128.65

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Solution

The fourth proportional to 145.90, 201.81 and 128.65 is: 177.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.90 : 201.81 = 128.65 : x
  2. Step 2: Convert to fraction form
    145.90/201.81 = 128.65/x
  3. Step 3: Cross multiply
    145.90x = 201.81 × 128.65
  4. Step 4: Simplify right side
    145.90x = 25,962.86
  5. Step 5: Solve for x
    x = 25,962.86/145.90
  6. Step 6: Final answer
    x = 177.95

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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.