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Finding the Fourth Proportional to 289.58, 399.78 and 281.39

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Solution

The fourth proportional to 289.58, 399.78 and 281.39 is: 388.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.58 : 399.78 = 281.39 : x
  2. Step 2: Convert to fraction form
    289.58/399.78 = 281.39/x
  3. Step 3: Cross multiply
    289.58x = 399.78 × 281.39
  4. Step 4: Simplify right side
    289.58x = 112,492.10
  5. Step 5: Solve for x
    x = 112,492.10/289.58
  6. Step 6: Final answer
    x = 388.47

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.