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Finding the Fourth Proportional to 661.65, 912.78 and 495.87

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Solution

The fourth proportional to 661.65, 912.78 and 495.87 is: 684.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.65 : 912.78 = 495.87 : x
  2. Step 2: Convert to fraction form
    661.65/912.78 = 495.87/x
  3. Step 3: Cross multiply
    661.65x = 912.78 × 495.87
  4. Step 4: Simplify right side
    661.65x = 452,620.22
  5. Step 5: Solve for x
    x = 452,620.22/661.65
  6. Step 6: Final answer
    x = 684.08

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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.