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Finding the Fourth Proportional to 290.90, 436.45 and 128.59

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Solution

The fourth proportional to 290.90, 436.45 and 128.59 is: 192.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.90 : 436.45 = 128.59 : x
  2. Step 2: Convert to fraction form
    290.90/436.45 = 128.59/x
  3. Step 3: Cross multiply
    290.90x = 436.45 × 128.59
  4. Step 4: Simplify right side
    290.90x = 56,123.11
  5. Step 5: Solve for x
    x = 56,123.11/290.90
  6. Step 6: Final answer
    x = 192.93

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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.