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Finding the Fourth Proportional to 615.78, 924.21 and 399.60

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Solution

The fourth proportional to 615.78, 924.21 and 399.60 is: 599.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    615.78 : 924.21 = 399.60 : x
  2. Step 2: Convert to fraction form
    615.78/924.21 = 399.60/x
  3. Step 3: Cross multiply
    615.78x = 924.21 × 399.60
  4. Step 4: Simplify right side
    615.78x = 369,314.32
  5. Step 5: Solve for x
    x = 369,314.32/615.78
  6. Step 6: Final answer
    x = 599.75

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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.