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Finding the Fourth Proportional to 290.12, 435.78 and 280.40

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Solution

The fourth proportional to 290.12, 435.78 and 280.40 is: 421.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.12 : 435.78 = 280.40 : x
  2. Step 2: Convert to fraction form
    290.12/435.78 = 280.40/x
  3. Step 3: Cross multiply
    290.12x = 435.78 × 280.40
  4. Step 4: Simplify right side
    290.12x = 122,192.71
  5. Step 5: Solve for x
    x = 122,192.71/290.12
  6. Step 6: Final answer
    x = 421.18

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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.