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Finding the Fourth Proportional to 430.74, 642.83 and 419.80

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Solution

The fourth proportional to 430.74, 642.83 and 419.80 is: 626.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.74 : 642.83 = 419.80 : x
  2. Step 2: Convert to fraction form
    430.74/642.83 = 419.80/x
  3. Step 3: Cross multiply
    430.74x = 642.83 × 419.80
  4. Step 4: Simplify right side
    430.74x = 269,860.03
  5. Step 5: Solve for x
    x = 269,860.03/430.74
  6. Step 6: Final answer
    x = 626.50

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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.