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Finding the Fourth Proportional to 430.84, 643.15 and 419.91

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Solution

The fourth proportional to 430.84, 643.15 and 419.91 is: 626.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.84 : 643.15 = 419.91 : x
  2. Step 2: Convert to fraction form
    430.84/643.15 = 419.91/x
  3. Step 3: Cross multiply
    430.84x = 643.15 × 419.91
  4. Step 4: Simplify right side
    430.84x = 270,065.12
  5. Step 5: Solve for x
    x = 270,065.12/430.84
  6. Step 6: Final answer
    x = 626.83

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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.