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Finding the Fourth Proportional to 784.64, 1,176.64 and 399.68

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Solution

The fourth proportional to 784.64, 1,176.64 and 399.68 is: 599.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    784.64 : 1,176.64 = 399.68 : x
  2. Step 2: Convert to fraction form
    784.64/1,176.64 = 399.68/x
  3. Step 3: Cross multiply
    784.64x = 1,176.64 × 399.68
  4. Step 4: Simplify right side
    784.64x = 470,279.48
  5. Step 5: Solve for x
    x = 470,279.48/784.64
  6. Step 6: Final answer
    x = 599.36

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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.