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Finding the Fourth Proportional to 128.99, 193.47 and 42.34

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Solution

The fourth proportional to 128.99, 193.47 and 42.34 is: 63.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.99 : 193.47 = 42.34 : x
  2. Step 2: Convert to fraction form
    128.99/193.47 = 42.34/x
  3. Step 3: Cross multiply
    128.99x = 193.47 × 42.34
  4. Step 4: Simplify right side
    128.99x = 8,191.48
  5. Step 5: Solve for x
    x = 8,191.48/128.99
  6. Step 6: Final answer
    x = 63.50

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.