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Finding the Fourth Proportional to 289.90, 431.87 and 281.40

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Solution

The fourth proportional to 289.90, 431.87 and 281.40 is: 419.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.90 : 431.87 = 281.40 : x
  2. Step 2: Convert to fraction form
    289.90/431.87 = 281.40/x
  3. Step 3: Cross multiply
    289.90x = 431.87 × 281.40
  4. Step 4: Simplify right side
    289.90x = 121,528.22
  5. Step 5: Solve for x
    x = 121,528.22/289.90
  6. Step 6: Final answer
    x = 419.21

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.