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Finding the Fourth Proportional to 430.78, 642.67 and 395.54

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Solution

The fourth proportional to 430.78, 642.67 and 395.54 is: 590.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.78 : 642.67 = 395.54 : x
  2. Step 2: Convert to fraction form
    430.78/642.67 = 395.54/x
  3. Step 3: Cross multiply
    430.78x = 642.67 × 395.54
  4. Step 4: Simplify right side
    430.78x = 254,201.69
  5. Step 5: Solve for x
    x = 254,201.69/430.78
  6. Step 6: Final answer
    x = 590.10

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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.