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Finding the Fourth Proportional to 206.64, 285.20 and 128.01

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Solution

The fourth proportional to 206.64, 285.20 and 128.01 is: 176.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.64 : 285.20 = 128.01 : x
  2. Step 2: Convert to fraction form
    206.64/285.20 = 128.01/x
  3. Step 3: Cross multiply
    206.64x = 285.20 × 128.01
  4. Step 4: Simplify right side
    206.64x = 36,507.81
  5. Step 5: Solve for x
    x = 36,507.81/206.64
  6. Step 6: Final answer
    x = 176.67

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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.