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Finding the Fourth Proportional to 421.78, 582.15 and 274.15

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Solution

The fourth proportional to 421.78, 582.15 and 274.15 is: 378.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.78 : 582.15 = 274.15 : x
  2. Step 2: Convert to fraction form
    421.78/582.15 = 274.15/x
  3. Step 3: Cross multiply
    421.78x = 582.15 × 274.15
  4. Step 4: Simplify right side
    421.78x = 159,597.38
  5. Step 5: Solve for x
    x = 159,597.38/421.78
  6. Step 6: Final answer
    x = 378.39

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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.