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Finding the Fourth Proportional to 421.78, 632.40 and 361.30

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Solution

The fourth proportional to 421.78, 632.40 and 361.30 is: 541.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.78 : 632.40 = 361.30 : x
  2. Step 2: Convert to fraction form
    421.78/632.40 = 361.30/x
  3. Step 3: Cross multiply
    421.78x = 632.40 × 361.30
  4. Step 4: Simplify right side
    421.78x = 228,486.12
  5. Step 5: Solve for x
    x = 228,486.12/421.78
  6. Step 6: Final answer
    x = 541.72

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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.