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Finding the Fourth Proportional to 421.15, 632.63 and 407.31

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Solution

The fourth proportional to 421.15, 632.63 and 407.31 is: 611.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.15 : 632.63 = 407.31 : x
  2. Step 2: Convert to fraction form
    421.15/632.63 = 407.31/x
  3. Step 3: Cross multiply
    421.15x = 632.63 × 407.31
  4. Step 4: Simplify right side
    421.15x = 257,676.44
  5. Step 5: Solve for x
    x = 257,676.44/421.15
  6. Step 6: Final answer
    x = 611.84

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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.