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Finding the Fourth Proportional to 145.80, 217.44 and 128.16

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Solution

The fourth proportional to 145.80, 217.44 and 128.16 is: 191.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.80 : 217.44 = 128.16 : x
  2. Step 2: Convert to fraction form
    145.80/217.44 = 128.16/x
  3. Step 3: Cross multiply
    145.80x = 217.44 × 128.16
  4. Step 4: Simplify right side
    145.80x = 27,867.11
  5. Step 5: Solve for x
    x = 27,867.11/145.80
  6. Step 6: Final answer
    x = 191.13

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.