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Finding the Fourth Proportional to 639.30, 950.64 and 619.80

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Solution

The fourth proportional to 639.30, 950.64 and 619.80 is: 921.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.30 : 950.64 = 619.80 : x
  2. Step 2: Convert to fraction form
    639.30/950.64 = 619.80/x
  3. Step 3: Cross multiply
    639.30x = 950.64 × 619.80
  4. Step 4: Simplify right side
    639.30x = 589,206.67
  5. Step 5: Solve for x
    x = 589,206.67/639.30
  6. Step 6: Final answer
    x = 921.64

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.