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Finding the Fourth Proportional to 421.30, 628.76 and 397.31

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Solution

The fourth proportional to 421.30, 628.76 and 397.31 is: 592.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.30 : 628.76 = 397.31 : x
  2. Step 2: Convert to fraction form
    421.30/628.76 = 397.31/x
  3. Step 3: Cross multiply
    421.30x = 628.76 × 397.31
  4. Step 4: Simplify right side
    421.30x = 249,810.49
  5. Step 5: Solve for x
    x = 249,810.49/421.30
  6. Step 6: Final answer
    x = 592.95

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.