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Finding the Fourth Proportional to 479.40, 661.53 and 280.25

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Solution

The fourth proportional to 479.40, 661.53 and 280.25 is: 386.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    479.40 : 661.53 = 280.25 : x
  2. Step 2: Convert to fraction form
    479.40/661.53 = 280.25/x
  3. Step 3: Cross multiply
    479.40x = 661.53 × 280.25
  4. Step 4: Simplify right side
    479.40x = 185,393.78
  5. Step 5: Solve for x
    x = 185,393.78/479.40
  6. Step 6: Final answer
    x = 386.72

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.