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Finding the Fourth Proportional to 290.99, 436.39 and 128.79

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Solution

The fourth proportional to 290.99, 436.39 and 128.79 is: 193.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.99 : 436.39 = 128.79 : x
  2. Step 2: Convert to fraction form
    290.99/436.39 = 128.79/x
  3. Step 3: Cross multiply
    290.99x = 436.39 × 128.79
  4. Step 4: Simplify right side
    290.99x = 56,202.35
  5. Step 5: Solve for x
    x = 56,202.35/290.99
  6. Step 6: Final answer
    x = 193.14

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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.