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Finding the Fourth Proportional to 616.65, 851.21 and 420.42

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Solution

The fourth proportional to 616.65, 851.21 and 420.42 is: 580.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    616.65 : 851.21 = 420.42 : x
  2. Step 2: Convert to fraction form
    616.65/851.21 = 420.42/x
  3. Step 3: Cross multiply
    616.65x = 851.21 × 420.42
  4. Step 4: Simplify right side
    616.65x = 357,868.37
  5. Step 5: Solve for x
    x = 357,868.37/616.65
  6. Step 6: Final answer
    x = 580.35

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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.