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Finding the Fourth Proportional to 643.74, 960.99 and 561.75

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Solution

The fourth proportional to 643.74, 960.99 and 561.75 is: 838.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.74 : 960.99 = 561.75 : x
  2. Step 2: Convert to fraction form
    643.74/960.99 = 561.75/x
  3. Step 3: Cross multiply
    643.74x = 960.99 × 561.75
  4. Step 4: Simplify right side
    643.74x = 539,836.13
  5. Step 5: Solve for x
    x = 539,836.13/643.74
  6. Step 6: Final answer
    x = 838.59

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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.