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Finding the Fourth Proportional to 290.39, 435.75 and 128.08

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Solution

The fourth proportional to 290.39, 435.75 and 128.08 is: 192.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.39 : 435.75 = 128.08 : x
  2. Step 2: Convert to fraction form
    290.39/435.75 = 128.08/x
  3. Step 3: Cross multiply
    290.39x = 435.75 × 128.08
  4. Step 4: Simplify right side
    290.39x = 55,810.92
  5. Step 5: Solve for x
    x = 55,810.92/290.39
  6. Step 6: Final answer
    x = 192.20

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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.