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Finding the Fourth Proportional to 661.49, 912.57 and 395.78

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Solution

The fourth proportional to 661.49, 912.57 and 395.78 is: 546.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.49 : 912.57 = 395.78 : x
  2. Step 2: Convert to fraction form
    661.49/912.57 = 395.78/x
  3. Step 3: Cross multiply
    661.49x = 912.57 × 395.78
  4. Step 4: Simplify right side
    661.49x = 361,176.95
  5. Step 5: Solve for x
    x = 361,176.95/661.49
  6. Step 6: Final answer
    x = 546.01

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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.