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Finding the Fourth Proportional to 290.85, 436.49 and 128.66

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Solution

The fourth proportional to 290.85, 436.49 and 128.66 is: 193.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.85 : 436.49 = 128.66 : x
  2. Step 2: Convert to fraction form
    290.85/436.49 = 128.66/x
  3. Step 3: Cross multiply
    290.85x = 436.49 × 128.66
  4. Step 4: Simplify right side
    290.85x = 56,155.98
  5. Step 5: Solve for x
    x = 56,155.98/290.85
  6. Step 6: Final answer
    x = 193.08

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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.