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Finding the Fourth Proportional to 147.80, 203.82 and 128.12

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Solution

The fourth proportional to 147.80, 203.82 and 128.12 is: 176.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    147.80 : 203.82 = 128.12 : x
  2. Step 2: Convert to fraction form
    147.80/203.82 = 128.12/x
  3. Step 3: Cross multiply
    147.80x = 203.82 × 128.12
  4. Step 4: Simplify right side
    147.80x = 26,111.92
  5. Step 5: Solve for x
    x = 26,111.92/147.80
  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.