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Finding the Fourth Proportional to 440.78, 661.40 and 258.53

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Solution

The fourth proportional to 440.78, 661.40 and 258.53 is: 387.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    440.78 : 661.40 = 258.53 : x
  2. Step 2: Convert to fraction form
    440.78/661.40 = 258.53/x
  3. Step 3: Cross multiply
    440.78x = 661.40 × 258.53
  4. Step 4: Simplify right side
    440.78x = 170,987.14
  5. Step 5: Solve for x
    x = 170,987.14/440.78
  6. Step 6: Final answer
    x = 387.92

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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.