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Finding the Fourth Proportional to 290.70, 436.19 and 128.50

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Solution

The fourth proportional to 290.70, 436.19 and 128.50 is: 192.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.70 : 436.19 = 128.50 : x
  2. Step 2: Convert to fraction form
    290.70/436.19 = 128.50/x
  3. Step 3: Cross multiply
    290.70x = 436.19 × 128.50
  4. Step 4: Simplify right side
    290.70x = 56,048.68
  5. Step 5: Solve for x
    x = 56,048.68/290.70
  6. Step 6: Final answer
    x = 192.81

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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.