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Finding the Fourth Proportional to 643.75, 965.79 and 278.45

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Solution

The fourth proportional to 643.75, 965.79 and 278.45 is: 417.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.75 : 965.79 = 278.45 : x
  2. Step 2: Convert to fraction form
    643.75/965.79 = 278.45/x
  3. Step 3: Cross multiply
    643.75x = 965.79 × 278.45
  4. Step 4: Simplify right side
    643.75x = 268,918.00
  5. Step 5: Solve for x
    x = 268,918.00/643.75
  6. Step 6: Final answer
    x = 417.74

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.