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Finding the Fourth Proportional to 421.04, 630.91 and 215.66

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Solution

The fourth proportional to 421.04, 630.91 and 215.66 is: 323.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.04 : 630.91 = 215.66 : x
  2. Step 2: Convert to fraction form
    421.04/630.91 = 215.66/x
  3. Step 3: Cross multiply
    421.04x = 630.91 × 215.66
  4. Step 4: Simplify right side
    421.04x = 136,060.35
  5. Step 5: Solve for x
    x = 136,060.35/421.04
  6. Step 6: Final answer
    x = 323.16

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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.