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Finding the Fourth Proportional to 669.36, 1,004.40 and 258.78

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Solution

The fourth proportional to 669.36, 1,004.40 and 258.78 is: 388.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.36 : 1,004.40 = 258.78 : x
  2. Step 2: Convert to fraction form
    669.36/1,004.40 = 258.78/x
  3. Step 3: Cross multiply
    669.36x = 1,004.40 × 258.78
  4. Step 4: Simplify right side
    669.36x = 259,918.63
  5. Step 5: Solve for x
    x = 259,918.63/669.36
  6. Step 6: Final answer
    x = 388.31

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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.