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Finding the Fourth Proportional to 155.66, 215.08 and 128.01

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Solution

The fourth proportional to 155.66, 215.08 and 128.01 is: 176.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.66 : 215.08 = 128.01 : x
  2. Step 2: Convert to fraction form
    155.66/215.08 = 128.01/x
  3. Step 3: Cross multiply
    155.66x = 215.08 × 128.01
  4. Step 4: Simplify right side
    155.66x = 27,532.39
  5. Step 5: Solve for x
    x = 27,532.39/155.66
  6. Step 6: Final answer
    x = 176.88

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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.