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Finding the Fourth Proportional to 615.67, 849.93 and 420.21

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Solution

The fourth proportional to 615.67, 849.93 and 420.21 is: 580.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    615.67 : 849.93 = 420.21 : x
  2. Step 2: Convert to fraction form
    615.67/849.93 = 420.21/x
  3. Step 3: Cross multiply
    615.67x = 849.93 × 420.21
  4. Step 4: Simplify right side
    615.67x = 357,149.09
  5. Step 5: Solve for x
    x = 357,149.09/615.67
  6. Step 6: Final answer
    x = 580.10

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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.