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Finding the Fourth Proportional to 699.09, 1,047.75 and 287.75

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Solution

The fourth proportional to 699.09, 1,047.75 and 287.75 is: 431.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    699.09 : 1,047.75 = 287.75 : x
  2. Step 2: Convert to fraction form
    699.09/1,047.75 = 287.75/x
  3. Step 3: Cross multiply
    699.09x = 1,047.75 × 287.75
  4. Step 4: Simplify right side
    699.09x = 301,484.82
  5. Step 5: Solve for x
    x = 301,484.82/699.09
  6. Step 6: Final answer
    x = 431.25

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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.