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Finding the Fourth Proportional to 698.51, 1,047.44 and 643.79

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Solution

The fourth proportional to 698.51, 1,047.44 and 643.79 is: 965.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    698.51 : 1,047.44 = 643.79 : x
  2. Step 2: Convert to fraction form
    698.51/1,047.44 = 643.79/x
  3. Step 3: Cross multiply
    698.51x = 1,047.44 × 643.79
  4. Step 4: Simplify right side
    698.51x = 674,327.17
  5. Step 5: Solve for x
    x = 674,327.17/698.51
  6. Step 6: Final answer
    x = 965.38

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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.